differentialadj.n.

Brit.

/ˌdɪfəˈrɛnʃl/, U.S.

/ˌdɪfəˈrɛn(t)ʃ(ə)l/

Forms: 1600s differentiall, 1600s– differential.

Origin: A borrowing from Latin. Etymon: Latin differentialis.

Etymology: < post-classical Latin differentialis of or relating to difference or diversity (9th cent.), illustrative of difference (late 13th cent. in a British source), (in logic) distinguished by specific difference (14th cent. in a British source) < differentia difference n.¹ + -ālis -al suffix¹. Compare Italian differenziale (15th cent.).In sense A. 3 after French différentiel (1696 or earlier in this sense). In sense A. 4 originally after French diagnostic différentiel (1820 or earlier). In sense B. 2 after post-classical Latin differentialis, in differentialis numerus ( J. Napier Mirifici logarithmorum canonis descriptio (1614) i. iii. 8; 1627 in Kepler's Tabulae Rudolphinae). The logarithm was so called because the logarithm of the tangent is the difference between the logarithm of the sine and the logarithm of the cosine.

A. adj.

1. Designating a mark or feature that serves to distinguish one thing from another; distinguishing, distinctive.

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the world > relative properties > relationship > difference > [adjective] > differentiating or distinctive

discretive?1490

differencing1603

differential1615

specificative1641

discriminating1642

discriminative1646

specializing1701

differentiating1794

diacritical1857

1615 E. Weston Triall Christian Truth: 2nd Pt. iv. 20 Man doeth accomplish his chiefest charge, assigned him by nature, by no other facultie in him, then such as is his owen by specificall and differentiall peculiaritie, as by his will and reason.

1652 J. Gaule Πυς-μαντια 78 Any quality of sympathy, or antipathy (which doe follow naturally the specifick, or differentiall forms).

1733 G. Cheyne Eng. Malady ii. xi. 227 The great differential Marks of the Distemper will appear.

1761 tr. C. Batteux Course Belles Lettres II. ii. ii. 268 It [sc. tragic action] must likewise be of a nature to excite terror and pity; this is its differential mark, and what renders it properly tragic.

1851 T. De Quincey Ld. Carlisle on Pope in Tait's Edinb. Mag. Apr. 236/2 Every case in the law courts..presents some one differential feature peculiar to itself.

1893 F. Hall in Nation (N.Y.) 57 449/3 One of the differential peculiarities of a highly important division of the Hindus of olden times.

1909 Science 5 Mar. 396 Wilson..regards a second x-chromosome as the differential factor between male and female.

1932 M. B. Barr Stud. in Social & Legal Theories xviii. 140 Reason being the differential mark of man, his peculiar good should be discoverable in the activity of reason.

2007 L. Kramer Why Classical Music still Matters (2008) iii. 71 The fate of melody is the first great differential feature of classical music.

a. Of, relating to, or characterized by difference; depending on difference; (esp. of a tax or rate) differing according to circumstances.

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the world > relative properties > relationship > difference > [adjective]

othereOE

otherkinseOE

unilicheOE

elseOE

otherways?c1225

diversc1250

diverse1297

unlikea1300

likelessa1325

sundrya1325

contrariousc1340

nothera1375

strangec1380

anothera1382

otherwisea1393

diversed1393

differenta1400

differing?c1400

deparayll1413

disparable1413

disparail1413

dissemblable1413

party?a1439

unlikeningc1450

indifferent1513

distinct1523

repugnant1528

far1531

heterogene?1541

discrepant1556

mislike1570

contrary1576

distincted1577

another-gainesa1586

dispar1587

another gate1594

dislike1596

unresembling1598

heterogeneana1601

anothergates1604

heterogeneal1605

unmatched1606

disparate1608

disparent?1611

differential1618

dissimilar1621

disparated1624

dissimilary1624

heterogeneous1624

unparallel1624

otherguess1632

anotherguise1635

incongenerous1646

anotherguess1650

otherguise1653

distant1654

unresemblant1655

distantial1656

allogeneous1666

distinguished1736

otherguised1768

unsimilar1768

insimilar1801

anotherkins1855

diff1861

distinctive1867

othergate1903

unalike1934

1618 J. Falconer Briefe Refut. ii. ii. 72 This differentiall law of meates is cerimoniall also, and no morall part of Moyses law.

1647 H. More Philos. Poems 20 This be understood Of differentiall profunditie.

1781 Monthly Rev. Aug. 142 They only represent the differential variations of the places of the nodes and inclinations.

1799 Morning Chron. 10 Oct. 3/3 An analysis, religious, moral, political, historical, zoological, comparative or differential, geographical, arithmetical, mathematical, &c. &c. should therefore be produced forthwith.

1841–8 F. Myers Catholic Thoughts II. iii. xxiv. 90 This testimony does not decide..the differential amount of sacredness between Substantial Divinity and Literal Infallibility.

1843 Ann. Reg. 1842 Hist. Europe 86/2 The interests of trade will be promoted by the repeal or reduction of various prohibitory and differential duties.

1894 A. Jessopp Random Roaming ii. 60 They compounded for murder according to a differential tariff.

1912 S. J. Chapman Polit. Econ. viii. 205 Super-marginal land earns its marginal worth plus an extra sum..which measures the differential advantages enjoyed by it.

1965 Listener 20 May 728/2 The present government..may take the principle of differential interest rates still further.

2007 N.Y. Rev. Bks. 22 Nov. 40/3 Clark calls this pattern of differential fertility of the well off the ‘survival of the richest’.

b. Science Relating to or involving a difference between two or more physical quantities; (of a physical action or effect) differing according to place, time, or circumstances; not uniform.

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1768 A. Tucker Light of Nature Pursued II. ii. 74 Weight is made by the differential, not the absolute pressure of ether.

1877 J. Le Conte Elements Geol. (1879) i. 55 The centre of the glacier moved faster than the margins. This differential motion is the capital discovery in relation to the motion of glaciers.

1891 C. L. Morgan Animal Life & Intell. v. 169 Physiologically, the effects of use or disuse are, in the main, effects on the relative nutrition, and hence on the differential growth of organs.

1900 Geogr. Jrnl. 15 652 The facts collected pointed to the conclusion that this type of valley was due to differential preglacial decay, with subsequent ice-erosion.

1925 H. C. Booth tr. F. Auerbach Mod. Magnetics (U.K. ed.) vi. 122 Light composed of various wave lengths, on passing from one medium to another undergoes differential refraction.

1957 E. W. Sinnott Matter, Mind & Man (1958) iii. 26 Almost from the start the embryo's growth is differential, more rapid in some directions than it is in others.

1973 New Scientist 22 Mar. (Instrument Suppl.) 16/1 Circular dichroism, the differential absorption of left and right circularly polarised light.

2009 E. J. Anthony Shore Processes & Palaeoenvironmental Applic. viii. 392 The presence of lichen in certain areas shows that erosion is differential.

c. Mechanics. Designating an instrument or apparatus which operates with different rates or directions of motion, or which records differences in physical values.Recorded earliest in differential thermometer n. at Compounds.

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1804 J. Leslie Heat 9 The instrument most essential in this research..was the differential thermometer.

1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 433 The differential galvanometer, an instrument in which there are two coils, the currents in which are independent of each other.

1908 Westm. Gaz. 16 Jan. 4/2 In conformity with the latest ideas in live-axle construction, the differential case is assembled horizontally.

1925 Morris Owner's Man. 26 If any adjustments to the differential bearings are required.

2007 P. P. Teodorescu Mech. Syst., Classical Models I. iv. 254 In the case of a differential hoist, the drum is constituted of two cylindrical sections of different radii.

3. Mathematics. Relating to or involving differentials (sense B. 1) or differentiation.Recorded earliest in differential calculus n. at Compounds.In early use frequently with reference to the form of calculus developed by Leibniz, in contrast to that developed by Newton (cf. fluxional adj. 1).

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the world > relative properties > number > calculus > [adjective]

differential1702

incremental1716

differentio-differential1728

fluxionary1734

fluxional1749

residual1758

Abelian1846

calcular1855

integro-differential1914

1702 J. Raphson Math. Dict. at Fluxions A different way..passes..in France under the Name of Leibnitz's Differential Calculus, or Calculus of Differences.

1712 J. Collins et al. Commercium Epistolicum 121 The Differential Method is one and the same with the Method of Fluxions, excepting the Name and Mode of Notation.

1759 New Universal Hist. Arts & Sci. II. 12/2 If you make the given value equal to the differential expression, and either sum up the differential equation, or, if that cannot be, construct it, the curve required, is had.

1809 J. S. Pond tr. P. S. Laplace Syst. World II. iv. vii. 130 A remarkable equation.., led me, without the aid of integrations, and by differential methods only, to general expressions, for the radii of spheroids.

1834 Q. Jrnl. Educ. 8 101 That the differential notation possessed many advantages over the fluxional was soon almost universally admitted.

1909 F. R. Jones Gas Engine xix. 369 The width of each strip is then represented by the differential quantity dV.

1972 Proc. Amer. Math. Soc. 31 632 Let L(y) be a linear differential expression of order n with continuous coefficients and with leading coefficient equal to one.

2007 M. Schlosshauer Decoherence (2008) iii. 127 Taking the differential limit of small T, we obtain our final result.

4. Medicine. Designating a diagnosis, or method of diagnosis, which involves differentiating between two or more conditions which share similar symptoms or signs. Chiefly in differential diagnosis.

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the world > health and disease > healing > diagnosis or prognosis > [adjective] > diagnostic > of specific methods of diagnosis

uromantical1623

differential1829

urinoscopic1889

scatologic1891

radiodiagnostic1907

immunodiagnostic1911

serological1911

scatological1924

non-invasive1968

1829 tr. A. Cazenave & H. E. Schedel Pract. Synopsis Cutaneous Dis. 97 As to the other forms of herpes, as they only differ in their form and their seat, these circumstances form a sufficient differential diagnosis.

1877 F. T. Roberts Handbk. Med. (ed. 3) I. 19 In others the diagnosis has to be more or less differential.

1919 W. E. Chancellor Health Teacher iii. 33 That all diagnosis is differential everyone has heard and many appreciate.

1944 E. A. Strecker Fund. Psychiatry vii. 123 In spite of the fact that schizophrenia and manic-depressive are divergent.., there are clinical situations in which the differential diagnosis is difficult.

1968 New Eng. Jrnl. Med. 1 Feb. 269/1 In the differential diagnosis of myasthenia the following conditions are most often mistaken for myasthenia: fatigue states due to emotional factors..; metabolic disorders associated with muscle weakness, such as hyperthyroidism; primary diseases of muscle, such as dystrophy and myositis, [etc.].

2012 N.Y. Rev. Bks. 24 May 4/1 The aim was to generate comprehensive lists of possible causes for the patient's symptoms and physical findings, so-called ‘differential diagnoses’.

B. n.

1. Mathematics. Originally: a notional infinitesimally small change in the value of a varying quantity. In later use chiefly: the product of the derivative of a given function and an independent variable, representing a linear approximation of small changes in the value of a function. Frequently with of, specifying the function in question.The formula for the differential of a single-variable function f(x), denoted df is frequently given as df = f′(x) dx, where f'(x) is the derivative of f(x) and x and dx are independent variables.

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the world > relative properties > number > calculus > [noun] > differential calculus > differentiation > differential

differential1702

moment1706

momentane1706

increment1721

element1728

momentum1735

H1872

interval1918

differentio-differential1939

1702 J. Harris New Short Treat. Algebra 117 This Method is much more natural and shorter..with the Differential d Multiplied into the Flowing Quantity, to denote the Fluxion.

1788 G. S. Howard New Royal Encycl. I. 424 Multiply the differential of [each] factor into the other factor, the sum of the two [products] is the differential sought.

1818 R. Woodhouse Elem. Treat. Astron. II. 392 We must now find dv in terms of the differentials of n t and of e.

1871 W. G. Peck Pract. Treat. Differential & Integral Calculus v. iii. 207 The product of this [sc. the derivative of y] by the differential of the variable is the differential of y.

1920 Biometrika 13 10 To get the Gaussian or normal curve we must..replace differences by differentials.

2004 R. Cooke tr. V. A. Zorich Math. Anal. I. v. 193 Although the problems of finding the differential and finding the derivative are mathematically equivalent, the derivative and the differential are nevertheless not the same thing.

†2. Mathematics. The logarithm of the tangent of an angle. Obsolete. rare.Apparently only attested in dictionaries or glossaries.

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1728 E. Chambers Cycl. Differential, in the Doctrine of Logarithms. Kepler calls the Logarithms of Tangents, Differentiales; which we usually call Artificial Tangents.

a. An arrangement of gears that transmits equal power to each of a pair of wheels while allowing them to rotate at different speeds, used esp. in a motor vehicle to facilitate cornering; = differential gear n. at Compounds.

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society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear

differential gearing1842

differential gear1855

differential1872

1872 U.S. Patent 125,501 2/2 A flange..covers and protects the groove of the skip-wheel and the teeth of the differentials.

1902 Daily Chron. 30 June 6/2 He broke the differential of his 70 h.-p. Panhard car 50 kilometres from the finish.

1930 J. B. Priestley Angel Pavement ii. 72 Wanted new plugs and mag. and brakes re-lining and something doing to the differential.

1959 Motor Man. (ed. 36) iv. 94 The differential naturally moves up and down in relation to the chassis whenever the wheels meet a bump.

2006 J. Scott How to rebuild & modify your Muscle Car viii. 128/2 Three basic types of differentials are available.

†b. A differential winding (differential winding n. at Compounds); a galvanometer or similar electrical instrument employing a differential winding. Also: an arc lamp of relatively high resistance compared with other lamps in a series; the conductor in such a lamp. Obsolete. rare.

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1880 Jrnl. Soc. Telegr. Engineers 9 87 Does not an ordinary two wire differential coil to some extent resemble the two coil differential in the distribution of its two wires.

1884 E. H. Knight Pract. Dict. Mech. Suppl. Differential (Electricity), a coil of electrified wire having such relation to another electrified coil or to an armature (or needle) common to both as to produce polar action contrary to that produced by such other coil. (Electric Lamps), a conductor of high relative resistance—used with electric lamps in series,—which operates in the twofold capacity of shunting surplus current to the next lamp, and of shortening the arc of its own lamp, so as to maintain equal action in all lamps of the series.

1897 Electr. Age 3 July 10/1 The differentials secure a stable current when working on a part of the characteristic curve back of that where the heavy droop occurs.

a. A difference in the charges levied or prices charged for a particular type of thing.

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society > trade and finance > charges > [noun] > as determined by specific conditions

rate1540

differential1879

1879 10th Ann. Rep. Board Railroad Commissioners (Mass.) 414 During that period the Central Vermont has operated under fixed differentials.

1890 Spectator 20 Sept. 383 The morality of American Railway Companies as regards..differentials and commissions.

1922 Colonial Tariff Policies (U.S. Tariff Comm.) i. 36 The term ‘free trade’ is frequently used loosely in reference to open-door régimes—that is, régimes whose characteristic feature is not absence of duties but absence of differentials.

1959 Punch 19 Aug. 30/2 The rise of Oundle's fees to £435 puts the school within £25 of Eton... What does Eton do now? Does it preserve its status by leaping ahead.., or does it get the Headmasters' Conference to negotiate a national agreement on differentials?

1965 New Statesman 23 Apr. 634/2 The major companies have reacted with countrywide cuts of 1d., 1½d. or 2d. off certain grades [of petrol]. Some..cut-price companies have followed suit, to try to keep their 3d. differential.

2008 L. Kaplow Theory Taxation & Public Econ. vi. 142 It is hardly obvious what sort of differentials in commodity taxation are justified on account of difficulties with income tax enforcement.

2009 Wall St. Jrnl. 2 June r6/2 The price differential between a feature phone and a smart phone has narrowed to the point where lots of people are migrating.

b. A difference in wages between industries or between categories of employees in the same industry.Recorded earliest in wage differential n. at wage n. Compounds 3b; see also pay differential n. at pay n. Compounds 3.

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society > trade and finance > fees and taxes > payment for labour or service > wage structures and scales > [noun] > wage scale > relative grading of salaries > differential

differential1894

wage differential1950

1894 Nation (N.Y.) 24 May 381/2 This series of wage differentials, as we may call it, has long been a matter requiring delicate treatment.

1941 Economist 8 Feb. 178/2 The present economic differentials between one occupation and another and one status and another are, over a wide field, calculated to make people stay where they are.

1955 Times 17 June 4/4 This trend would lift the skilled differential and the future might show a relative improvement in payment for skill.

2011 T. Brown-Nagin Courage to Dissent iv. 92 The judge held salary differentials between Atlanta's African-American and white teachers patently unconstitutional.

5. Biology. A distinguishing biological characteristic of an organism, species, etc.; a measure of to what degree a given organism or species differs (in some respect) from others.

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society > communication > indication > that which identifies or distinguishes > [noun]

tokenc1000

distinctionc1374

differencea1398

signeta1425

knowledge?c1475

smell?a1505

markc1522

badge1529

note1583

impress1590

monument1590

type1595

stamp1600

pressure1604

mintage1612

criterion1613

impressa1628

differencer1633

lineament1638

mole1644

discrimination1646

tessera1647

diagnostic1651

monumental1657

discretive1660

signate1662

footmark1666

trait1752

memorandum1766

fingerprint1792

insignia1796

identifier1807

designative1824

cachet1840

differentiator1854

tanga1867

trademark1869

signature1873

totem1875

differential1883

earmarkings1888

paw print1894

discriminator1943

ident1952

1883 A. Hyatt in Proc. 32nd Meeting Amer. Assoc. Advancem. Sci. (1884) 358 During their subsequent history, characteristics are divisible into two categories: those which become morphological equivalents and are essentially similar in distinct series, and those which are essentially different in distinct series and may be classed as morphological differentials.

1913 Amer. Naturalist 47 36 One ought to be able to measure and correlate the differentials between organisms.

1953 Proc. National Acad. Sci. U.S.A. 39 128 In contrast to the organismal differentials which are the same in the different parts of an organism, we must distinguish the differentials of the various organs and tissues.

1988 T. G. Wolcott in W. W. Burggren & B. R. McMahon Biol. Land Crabs iii. 96 Controlled laboratory studies and field experiments will be needed to quantify differentials in requirements and exploitative abilities.

2011 C. C. Maley et al. in R. C. Fitzgerald Pre-Invasive Dis. vii. 115 The rate of clonal expansion depends on the relative fitness differential between a clone and its competitors.

Compounds

differential amplifier n. Electronics an amplifier which amplifies the difference between two inputs.

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1922 Brit. Patent 174,312 3/1 The differential amplifiers will build up the vocal or telephonic current to audible value in the receiver.

1951 Electroencephalography & Clin. Neurophysiol. 3 497/1 The action potentials were preamplified in a differential amplifier.

2012 Power Electronics Technol. (Nexis) 26 July The ac line current is measured using the differential amplifier, U1, connected across the shunt resistor, R1.

differential analyser n. now historical a device, typically an analogue computer, designed to solve differential equations.

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society > computing and information technology > hardware > computer > [noun] > analogue > differential analyser

differential analyser1930

1930 Engin. Abstr. (Inst. Civil Engineers Great Brit.) No. 45. 33 (heading) An Alternating-Current Differential Analyser and its Application to Harmonic Analysis.

1957 Technology July 188/1 The analogue laboratory contains a large electro-mechanical differential analyser.

2006 D. Edgerton Shock of Old (2008) i. 7 Digital electronic computers were preceded by mechanical analogue computers, from tide predictors to differential analysers.

differential calculus n. [after French calcul différentiel (1696 or earlier)] Mathematics the method of determining the tangent lines to curves through consideration of infinitesimally small changes of values (frequently with the); the branch of mathematics dealing with the properties of differentials and derivatives; cf. integral calculus at integral adj. 4b.In early use frequently with reference to the form of calculus developed by Leibniz, in contrast to that developed by Newton (cf. fluxional adj. 1).

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the world > relative properties > number > calculus > [noun] > differential calculus

differential calculus1702

tetragonistic(al calculus1727

1702Differential Calculus [see sense A. 3].

1790 Monthly Rev. 2 532 Having found, by means of the differential calculus, an equation of the radius osculator and amplitude of a curve..the author reduces it to co-ordinates.

1830 J. F. W. Herschel Prelim. Disc. Study Nat. Philos. iii. iii. 271 The method of fluxions, or, as it is now more generally called, the differential calculus.

1956 F. Bagemihl tr. K. Knopp Infinite Sequences & Series i. 17 We also assume that the reader is familiar..with the rudiments of differential calculus and function theory.

2007 N.Y. Times Mag. 30 Sept. 94 Most engineering schools stress subjects like differential calculus and physics.

differential coefficient n. Mathematics a function which expresses the instantaneous rates of change of a given function at different points; = derivative n. 3.

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the world > relative properties > number > calculus > [noun] > differential calculus > differentiation > derivative

derivativea1690

fluxion1704

differential coefficient1708

differential coefficient1786

first derivative1852

1786 C. Hutton Tracts Math. & Philos. iii. 38 The powers of the quantity..will then diverge faster than the differential coefficients converge.

1852 T. G. Hall Treat. Differential & Integral Calculus (ed. 5) iii. 31 This process is called successive differentiation, and du/dx, dp/dx, dq/dx, &c. are called the first, second, third, &c. differential coefficients, or the first, second, third, &c. derivatives of u.

1933 Proc. Sect. Sci. Kon. Akad. Wetensch. Amsterdam 36 152 The differential coefficients of G make a jump.

1993 J. O. Bird Higher Engin. Math. v. 35 The differential coefficient of a constant is zero.

differential equation n. Mathematics an equation involving differentials or (now more commonly) derivatives.exact differential equation, partial differential equation: see the first element.

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1704 C. Hayes Treat. Fluxions 151 We have this Differential Equation..which expresses the Nature of the Curve requir'd.

1895 Ann. Math. 9 65 Let us find the differential equations of the first order which are invariant.

2009 S. Blundell Superconductivity: Very Short Introd. vi. 73 They ended up with a pair of rather complicated differential equations.

differential gear n. Mechanics an arrangement of gears that transmits equal power to each of a pair of wheels while allowing them to rotate at different speeds, used esp. in a motor vehicle to facilitate cornering.

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society > travel > means of travel > a conveyance > vehicle > vehicles according to means of motion > vehicle moving on wheels > [noun] > parts of vehicle moving on wheels > gear > differential gear

differential gearing1842

differential gear1855

diff1912

society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear

differential gearing1842

differential gear1855

differential1872

1855 Newton's London Jrnl. Arts & Sci. 1 340 Fig. 2, shews an arrangement of differential gear.

1938 J.-B. O. Sneeden Introd. Internal Combustion Engin. (new ed.) iv. 60 In 1927, the Citroën Gear Co. built a small oil engine with a single crankshaft and piston, but with a 2 to 1 differential gear between the connecting rod and the shaft.

2001 Automobile June 80/1 (advt.) We are gear cutters who specialise in making crownwheel & pinion sets & differential gears for all types of classic cars.

differential gearing n. Mechanics gearing that involves a differential gear.

ΘΚΠ

society > travel > means of travel > a conveyance > vehicle > vehicles according to means of motion > vehicle moving on wheels > [noun] > parts of vehicle moving on wheels > gear > differential gear

differential gearing1842

differential gear1855

diff1912

society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear

differential gearing1842

differential gear1855

differential1872

1842 J. B. F. Jouannin Brit. Patent 9415 (1855) 2 A machine composed of a clock and of a peculiar combination of wheelwork called by the Inventor differential gearing.

1918 Machinery Apr. 709/1 Differential gearing may be used to combine these drives and allow any variations in speed that may be required.

2003 P. R. Lord Handbk. Yarn Production vii. 169 The direction of lay is changed and so is the bobbin speed. This is usually accomplished by means of a pair of opposed cone pulleys and differential gearing.

differential gene expression n. Genetics variation in the expression (expression n. 7) of particular genes by different cells.

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1957 Bios 28 22 We must continue to explore them [sc. salivary-gland chromosomes] fully in our efforts to find a cytological basis for the differential expression of allelic genes.]

1963 Amer. Zoologist 3 134/1 Cellular differentiation is clearly a matter of differential gene expression.

1986 Jrnl. Molecular Biol. 191 431/1 Whether the regulation of this differential gene expression is exerted at the transcriptional or post-transcriptional level remains to be determined.

2001 New Scientist 16 June 90 (advt.) Research Assistant... Required for two years..to work on an exciting parasitology project funded by the Home of Rest for Horses, to study differential gene expression in cyathostomins.

differential geometry n. [after French géometrie différentielle (1854 in the passage translated in quot. 1877)] Mathematics the branch of mathematics concerned with the study of geometry by means of techniques from calculus.

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the world > relative properties > number > geometry > [noun] > branches of

planimetrya1393

conic?a1560

helicosophy1570

stereometry1570

spheric1660

planometry1669

mensuration1704

polygonometry1791

analytical geometry1802

isoperimetry1811

analytic geometry1817

algebraic geometry1821

coordinate geometry1837

non-Euclidean geometry1872

differential geometry1877

pangeometry1878

projective geometry1878

metageometry1890

Riemann geometry1895

variable geometry1957

1877 R. Congreve tr. A. Comte Syst. Positive Polity IV. iii. 177 Seven chapters will put into their proper shape the calculus..; preliminary geometry; algebraic geometry; differential geometry; integral geometry; and general mechanics.

1960 Tucson (Arizona) Daily Citizen 18 Feb. 39/1 The first universe-shaking idea that arose from differential geometry is that space is curved.

2010 G. G. Szpiro Math. Medley xix. 96 After formulating the theory of special relativity in 1905, Einstein spent the following decade intensively studying differential geometry.

differential GPS n. a form of GPS (GPS n. at G n. Initialisms) in which extremely accurate results are obtained by comparing the known positions of fixed ground stations with the same positions indicated by satellite.

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1981–2 Navigation Winter 353 Several of these applications are presented, including angle determination, single-channel differential GPS, area navigation and precision approach.

1992 In-Fisherman Feb. 48/2 After having spent millions on the SA-on/off system, an add-on called Differential GPS is rumored.

1998 Sunday Capital (Annapolis, Maryland) 22 Feb. c11/1 Coast Guard continually utilizes differential GPS to confirm positions.

differential lock n. Mechanics a device which disables the differential gear of a motor vehicle, forcing each of a pair of wheels to turn at the same speed; cf. diff lock n. at diff n.³ Compounds.A differential lock can be advantageous in maintaining traction, e.g. at high speed or on muddy or loose terrain.

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1914 Pop. Mech. Mar. 373/1 There is a differential lock by which the full tractive effort may be thrown on both rear wheels whenever necessary.

1988 Road & Track Nov. 93/1 Apparently BMW's automatically engaging viscous differential locks in the center and rear really get the job done.

2002 H. Heisler Adv. Vehicle Technol. (ed. 2) vii. 235/1 The differential lock has to be engaged manually by cable or compressed air.

differential psychology n. [after German differentielle Psychologie (1900 in the subtitle of a work by William Stern)] the scientific study of the differences between individuals in their thinking and behaviour.

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1900 Monist 11 140 Differential psychology studies, first individual differences per se, secondly their conditions and causes, and thirdly their forms of expression.

1958 A. C. Tolman Behavior & Psychol. Man p. viii The importance of differential psychology is now accepted so much as a matter of course that one is likely to forget that around 1920 the really dignified and important psychology was experimental.

2012 N.Y. Times (National ed.) 2 Nov. b13/1 Differential psychology, a field whose central question—What makes people behave and think differently from one another?—strikes at the heart of the age-old nature-nurture debate.

differential pulley n. Mechanics a pulley having a block with two rigidly connected wheels or sheaves of different diameters, the chain or rope unwinding from one as it winds on to the other.

ΘΚΠ

society > occupation and work > equipment > lifting or hoisting equipment > [noun] > tackle > pulley > types of

ram-head1611

pentaspast1702

differential pulley1833

jackanapes1844

well pulley1855

brake-pulley1873

1833 Repertory Patent Inventions 16 74 My [sc. J. Saxton's] invention consists in the application of pulleys of different diameters, which I denominate, ‘The differential Pulleys’.

1917 H. S. Carhart & H. N. Chute Physics with Applic. vi. 168 A practical advantage of the differential pulley is that there is always enough friction to keep the weight from dropping.

2009 O. A. Bauchau & J. I. Craig Struct. Anal. ix. 418 The mechanical advantage of the differential pulley increases as radii r_i and r₀ approach equal values.

differential scanning calorimeter n. an instrument for performing differential scanning calorimetry.

ΚΠ

1963 Jrnl. Sci. Instr. 40 470/2 Differential scanning calorimeter DSC-1. Perkin-Elmer Ltd... The DSC-1 measures the difference of electrical power required to maintain sample and reference materials at the same temperature while the temperature is varied.

1990 Omni July 97/3 With a differential scanning calorimeter,..a high-resolution optical microscope, and an advanced gas analyzer,..Rover is a rolling laboratory, capable of finding any carbonic remains or soil microbes.

2012 C. Ratti in J. Ahmed & S. Rahman Handbk. Food Process Design I. xxii. 632 The differential scanning calorimeter and freeze-drying microscope are two specialized techniques for determining important product properties related to freeze-drying.

differential scanning calorimetry n. a method of measuring the difference between the amounts of heat needed to increase the temperatures of a sample and a reference when the temperatures of both are changed in step with one another; abbreviated DSC.The principle behind differential scanning calorimetry is that when a sample undergoes a physical transformation as the temperature is varied, a different amount of heat will need to flow to it than to the reference to maintain both at equal temperatures. It can be used to measure various characteristic properties of a sample, including physical changes (as crystallization or melting) and chemical ones (as oxidation); it is also used as a quality control procedure.

ΚΠ

1965 Talanta 12 p. vii General Applications of Differential Scanning Calorimetry. A. P. Gray.

1990 Y. Doi Microbial Polyesters vii. 118 The crystallization and melting temperature..have been studied by the thermal analysis of differential scanning calorimetry (DSC) thermograms.

2009 Food Chem. 116 137 Differential scanning calorimetry was used to analyze gelatinization and retrogradation of waxy rice starch.

differential screw n. Mechanics a screw having two threads of different pitch in different parts of its length.The two threads might be of differing handedness (so that one unwinds as the other winds), or they may be of slightly different pitch (so as to generate small accurate movements corresponding to the difference of the pitches).

ΚΠ

1824 London Mechanics' Reg. 25 Dec. 114/1 (heading) The Differential Screw, invented by Mr. Perkins.

1916 Pop. Sci. Mar. 460 This differential screw consists of a combination of an 8-32 screw and a 2-56 screw.

2008 P. R. Yoder Mounting Optics Optical Instruments (ed. 2) ix. 386 Differential screws might be employed to advantage as the means for attaching the fixed ends of the tangent arms to the brackets.

differential thermometer n. a thermometer for measuring small changes or differences in temperature rather than actual temperature.The Beckmann thermometer, invented in 1905, is a common type of differential thermometer.

ΘΚΠ

the world > matter > properties of materials > temperature > measurement of temperature > [noun] > instrument > for detecting minute differences

differential thermometer1804

thermoscope1804

1804Differential thermometer [see sense A. 2c].

1923 Ecology 4 189 The instrument consists of a differential thermometer in a vacuum tube, which is connected with a recording apparatus.

2010 K. W. Whitten et al. Chemistry (ed. 9) xiv. 523 Specially constructed differential thermometers..measure small temperature changes accurately to the nearest 0.001°C.

differential tone n. [after German Differenzton (see difference tone n. at difference n.¹ Compounds)] Acoustics and Music a tone sometimes perceived during the simultaneous sounding of two other tones, its frequency being the difference between those of the tones being played; = difference tone n. at difference n.¹ Compounds; cf. summational tone at tone n. 2a(a).

ΚΠ

1864 A. J. Ellis in Proc. Royal Soc. 1863–4 13 393 The pitch of the principal and only one of these combinational tones necessary to be considered, is the difference of the pitch of its generating tones. It will therefore be termed the differential tone.

1908 E. H. Barton Text-bk. Sound vii. 384 To hear a differential tone, the generators should be high in pitch and preferably near together.

2005 M. Segell Devil's Horn (2006) ix. 192 François had studied the nature of differential tones, which are produced by two different notes sounding at once.

differential winding n. Electrical Engineering (in some electromagnets, galvanometers, transformers, etc.) a winding (winding n.¹ 8b) that is in the opposite direction to another (typically adjacent) winding, or that produces an effect that counters that of the other winding.

ΚΠ

1882 Official Gaz. (U.S. Patent Office) 28 Feb. 585/2 A local relay having a double set of differential windings or helices which form parts of local circuits.

1922 D. C. Jackson & J. P. Jackson Alternating Currents & Alternating Current Machinery (new ed.) xi. 656 The relay C consists of a U-shaped magnet core carrying a differential winding and provided with a pivoted armature which controls a circuit contact.

1992 S. H. Horowitz & A. G. Phadke Power Syst. Relaying viii. 205 Very small currents flow in the differential windings of the three relays during normal conditions.

This entry has been updated (OED Third Edition, March 2016; most recently modified version published online June 2022).

单词	differential
释义	differentialadj.n. Brit. /ˌdɪfəˈrɛnʃl/, U.S. /ˌdɪfəˈrɛn(t)ʃ(ə)l/ Forms: 1600s differentiall, 1600s– differential. Origin: A borrowing from Latin. Etymon: Latin differentialis. Etymology: < post-classical Latin differentialis of or relating to difference or diversity (9th cent.), illustrative of difference (late 13th cent. in a British source), (in logic) distinguished by specific difference (14th cent. in a British source) < differentia difference n.¹ + -ālis -al suffix¹. Compare Italian differenziale (15th cent.).In sense A. 3 after French différentiel (1696 or earlier in this sense). In sense A. 4 originally after French diagnostic différentiel (1820 or earlier). In sense B. 2 after post-classical Latin differentialis, in differentialis numerus ( J. Napier Mirifici logarithmorum canonis descriptio (1614) i. iii. 8; 1627 in Kepler's Tabulae Rudolphinae). The logarithm was so called because the logarithm of the tangent is the difference between the logarithm of the sine and the logarithm of the cosine. A. adj. 1. Designating a mark or feature that serves to distinguish one thing from another; distinguishing, distinctive. ΘΚΠ the world > relative properties > relationship > difference > [adjective] > differentiating or distinctive discretive?1490 differencing1603 differential1615 specificative1641 discriminating1642 discriminative1646 specializing1701 differentiating1794 diacritical1857 1615 E. Weston Triall Christian Truth: 2nd Pt. iv. 20 Man doeth accomplish his chiefest charge, assigned him by nature, by no other facultie in him, then such as is his owen by specificall and differentiall peculiaritie, as by his will and reason. 1652 J. Gaule Πυς-μαντια 78 Any quality of sympathy, or antipathy (which doe follow naturally the specifick, or differentiall forms). 1733 G. Cheyne Eng. Malady ii. xi. 227 The great differential Marks of the Distemper will appear. 1761 tr. C. Batteux Course Belles Lettres II. ii. ii. 268 It [sc. tragic action] must likewise be of a nature to excite terror and pity; this is its differential mark, and what renders it properly tragic. 1851 T. De Quincey Ld. Carlisle on Pope in Tait's Edinb. Mag. Apr. 236/2 Every case in the law courts..presents some one differential feature peculiar to itself. 1893 F. Hall in Nation (N.Y.) 57 449/3 One of the differential peculiarities of a highly important division of the Hindus of olden times. 1909 Science 5 Mar. 396 Wilson..regards a second x-chromosome as the differential factor between male and female. 1932 M. B. Barr Stud. in Social & Legal Theories xviii. 140 Reason being the differential mark of man, his peculiar good should be discoverable in the activity of reason. 2007 L. Kramer Why Classical Music still Matters (2008) iii. 71 The fate of melody is the first great differential feature of classical music. 2. a. Of, relating to, or characterized by difference; depending on difference; (esp. of a tax or rate) differing according to circumstances. ΘΚΠ the world > relative properties > relationship > difference > [adjective] othereOE otherkinseOE unilicheOE elseOE otherways?c1225 diversc1250 diverse1297 unlikea1300 likelessa1325 sundrya1325 contrariousc1340 nothera1375 strangec1380 anothera1382 otherwisea1393 diversed1393 differenta1400 differing?c1400 deparayll1413 disparable1413 disparail1413 dissemblable1413 party?a1439 unlikeningc1450 indifferent1513 distinct1523 repugnant1528 far1531 heterogene?1541 discrepant1556 mislike1570 contrary1576 distincted1577 another-gainesa1586 dispar1587 another gate1594 dislike1596 unresembling1598 heterogeneana1601 anothergates1604 heterogeneal1605 unmatched1606 disparate1608 disparent?1611 differential1618 dissimilar1621 disparated1624 dissimilary1624 heterogeneous1624 unparallel1624 otherguess1632 anotherguise1635 incongenerous1646 anotherguess1650 otherguise1653 distant1654 unresemblant1655 distantial1656 allogeneous1666 distinguished1736 otherguised1768 unsimilar1768 insimilar1801 anotherkins1855 diff1861 distinctive1867 othergate1903 unalike1934 1618 J. Falconer Briefe Refut. ii. ii. 72 This differentiall law of meates is cerimoniall also, and no morall part of Moyses law. 1647 H. More Philos. Poems 20 This be understood Of differentiall profunditie. 1781 Monthly Rev. Aug. 142 They only represent the differential variations of the places of the nodes and inclinations. 1799 Morning Chron. 10 Oct. 3/3 An analysis, religious, moral, political, historical, zoological, comparative or differential, geographical, arithmetical, mathematical, &c. &c. should therefore be produced forthwith. 1841–8 F. Myers Catholic Thoughts II. iii. xxiv. 90 This testimony does not decide..the differential amount of sacredness between Substantial Divinity and Literal Infallibility. 1843 Ann. Reg. 1842 Hist. Europe 86/2 The interests of trade will be promoted by the repeal or reduction of various prohibitory and differential duties. 1894 A. Jessopp Random Roaming ii. 60 They compounded for murder according to a differential tariff. 1912 S. J. Chapman Polit. Econ. viii. 205 Super-marginal land earns its marginal worth plus an extra sum..which measures the differential advantages enjoyed by it. 1965 Listener 20 May 728/2 The present government..may take the principle of differential interest rates still further. 2007 N.Y. Rev. Bks. 22 Nov. 40/3 Clark calls this pattern of differential fertility of the well off the ‘survival of the richest’. b. Science Relating to or involving a difference between two or more physical quantities; (of a physical action or effect) differing according to place, time, or circumstances; not uniform. ΚΠ 1768 A. Tucker Light of Nature Pursued II. ii. 74 Weight is made by the differential, not the absolute pressure of ether. 1877 J. Le Conte Elements Geol. (1879) i. 55 The centre of the glacier moved faster than the margins. This differential motion is the capital discovery in relation to the motion of glaciers. 1891 C. L. Morgan Animal Life & Intell. v. 169 Physiologically, the effects of use or disuse are, in the main, effects on the relative nutrition, and hence on the differential growth of organs. 1900 Geogr. Jrnl. 15 652 The facts collected pointed to the conclusion that this type of valley was due to differential preglacial decay, with subsequent ice-erosion. 1925 H. C. Booth tr. F. Auerbach Mod. Magnetics (U.K. ed.) vi. 122 Light composed of various wave lengths, on passing from one medium to another undergoes differential refraction. 1957 E. W. Sinnott Matter, Mind & Man (1958) iii. 26 Almost from the start the embryo's growth is differential, more rapid in some directions than it is in others. 1973 New Scientist 22 Mar. (Instrument Suppl.) 16/1 Circular dichroism, the differential absorption of left and right circularly polarised light. 2009 E. J. Anthony Shore Processes & Palaeoenvironmental Applic. viii. 392 The presence of lichen in certain areas shows that erosion is differential. c. Mechanics. Designating an instrument or apparatus which operates with different rates or directions of motion, or which records differences in physical values.Recorded earliest in differential thermometer n. at Compounds. ΚΠ 1804 J. Leslie Heat 9 The instrument most essential in this research..was the differential thermometer. 1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 433 The differential galvanometer, an instrument in which there are two coils, the currents in which are independent of each other. 1908 Westm. Gaz. 16 Jan. 4/2 In conformity with the latest ideas in live-axle construction, the differential case is assembled horizontally. 1925 Morris Owner's Man. 26 If any adjustments to the differential bearings are required. 2007 P. P. Teodorescu Mech. Syst., Classical Models I. iv. 254 In the case of a differential hoist, the drum is constituted of two cylindrical sections of different radii. 3. Mathematics. Relating to or involving differentials (sense B. 1) or differentiation.Recorded earliest in differential calculus n. at Compounds.In early use frequently with reference to the form of calculus developed by Leibniz, in contrast to that developed by Newton (cf. fluxional adj. 1). ΘΚΠ the world > relative properties > number > calculus > [adjective] differential1702 incremental1716 differentio-differential1728 fluxionary1734 fluxional1749 residual1758 Abelian1846 calcular1855 integro-differential1914 1702 J. Raphson Math. Dict. at Fluxions A different way..passes..in France under the Name of Leibnitz's Differential Calculus, or Calculus of Differences. 1712 J. Collins et al. Commercium Epistolicum 121 The Differential Method is one and the same with the Method of Fluxions, excepting the Name and Mode of Notation. 1759 New Universal Hist. Arts & Sci. II. 12/2 If you make the given value equal to the differential expression, and either sum up the differential equation, or, if that cannot be, construct it, the curve required, is had. 1809 J. S. Pond tr. P. S. Laplace Syst. World II. iv. vii. 130 A remarkable equation.., led me, without the aid of integrations, and by differential methods only, to general expressions, for the radii of spheroids. 1834 Q. Jrnl. Educ. 8 101 That the differential notation possessed many advantages over the fluxional was soon almost universally admitted. 1909 F. R. Jones Gas Engine xix. 369 The width of each strip is then represented by the differential quantity dV. 1972 Proc. Amer. Math. Soc. 31 632 Let L(y) be a linear differential expression of order n with continuous coefficients and with leading coefficient equal to one. 2007 M. Schlosshauer Decoherence (2008) iii. 127 Taking the differential limit of small T, we obtain our final result. 4. Medicine. Designating a diagnosis, or method of diagnosis, which involves differentiating between two or more conditions which share similar symptoms or signs. Chiefly in differential diagnosis. ΘΚΠ the world > health and disease > healing > diagnosis or prognosis > [adjective] > diagnostic > of specific methods of diagnosis uromantical1623 differential1829 urinoscopic1889 scatologic1891 radiodiagnostic1907 immunodiagnostic1911 serological1911 scatological1924 non-invasive1968 1829 tr. A. Cazenave & H. E. Schedel Pract. Synopsis Cutaneous Dis. 97 As to the other forms of herpes, as they only differ in their form and their seat, these circumstances form a sufficient differential diagnosis. 1877 F. T. Roberts Handbk. Med. (ed. 3) I. 19 In others the diagnosis has to be more or less differential. 1919 W. E. Chancellor Health Teacher iii. 33 That all diagnosis is differential everyone has heard and many appreciate. 1944 E. A. Strecker Fund. Psychiatry vii. 123 In spite of the fact that schizophrenia and manic-depressive are divergent.., there are clinical situations in which the differential diagnosis is difficult. 1968 New Eng. Jrnl. Med. 1 Feb. 269/1 In the differential diagnosis of myasthenia the following conditions are most often mistaken for myasthenia: fatigue states due to emotional factors..; metabolic disorders associated with muscle weakness, such as hyperthyroidism; primary diseases of muscle, such as dystrophy and myositis, [etc.]. 2012 N.Y. Rev. Bks. 24 May 4/1 The aim was to generate comprehensive lists of possible causes for the patient's symptoms and physical findings, so-called ‘differential diagnoses’. B. n. 1. Mathematics. Originally: a notional infinitesimally small change in the value of a varying quantity. In later use chiefly: the product of the derivative of a given function and an independent variable, representing a linear approximation of small changes in the value of a function. Frequently with of, specifying the function in question.The formula for the differential of a single-variable function f(x), denoted df is frequently given as df = f′(x) dx, where f'(x) is the derivative of f(x) and x and dx are independent variables. ΘΚΠ the world > relative properties > number > calculus > [noun] > differential calculus > differentiation > differential differential1702 moment1706 momentane1706 increment1721 element1728 momentum1735 H1872 interval1918 differentio-differential1939 1702 J. Harris New Short Treat. Algebra 117 This Method is much more natural and shorter..with the Differential d Multiplied into the Flowing Quantity, to denote the Fluxion. 1788 G. S. Howard New Royal Encycl. I. 424 Multiply the differential of [each] factor into the other factor, the sum of the two [products] is the differential sought. 1818 R. Woodhouse Elem. Treat. Astron. II. 392 We must now find dv in terms of the differentials of n t and of e. 1871 W. G. Peck Pract. Treat. Differential & Integral Calculus v. iii. 207 The product of this [sc. the derivative of y] by the differential of the variable is the differential of y. 1920 Biometrika 13 10 To get the Gaussian or normal curve we must..replace differences by differentials. 2004 R. Cooke tr. V. A. Zorich Math. Anal. I. v. 193 Although the problems of finding the differential and finding the derivative are mathematically equivalent, the derivative and the differential are nevertheless not the same thing. †2. Mathematics. The logarithm of the tangent of an angle. Obsolete. rare.Apparently only attested in dictionaries or glossaries. ΚΠ 1728 E. Chambers Cycl. Differential, in the Doctrine of Logarithms. Kepler calls the Logarithms of Tangents, Differentiales; which we usually call Artificial Tangents. 3. a. An arrangement of gears that transmits equal power to each of a pair of wheels while allowing them to rotate at different speeds, used esp. in a motor vehicle to facilitate cornering; = differential gear n. at Compounds. ΘΚΠ society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear differential gearing1842 differential gear1855 differential1872 1872 U.S. Patent 125,501 2/2 A flange..covers and protects the groove of the skip-wheel and the teeth of the differentials. 1902 Daily Chron. 30 June 6/2 He broke the differential of his 70 h.-p. Panhard car 50 kilometres from the finish. 1930 J. B. Priestley Angel Pavement ii. 72 Wanted new plugs and mag. and brakes re-lining and something doing to the differential. 1959 Motor Man. (ed. 36) iv. 94 The differential naturally moves up and down in relation to the chassis whenever the wheels meet a bump. 2006 J. Scott How to rebuild & modify your Muscle Car viii. 128/2 Three basic types of differentials are available. †b. A differential winding (differential winding n. at Compounds); a galvanometer or similar electrical instrument employing a differential winding. Also: an arc lamp of relatively high resistance compared with other lamps in a series; the conductor in such a lamp. Obsolete. rare. ΚΠ 1880 Jrnl. Soc. Telegr. Engineers 9 87 Does not an ordinary two wire differential coil to some extent resemble the two coil differential in the distribution of its two wires. 1884 E. H. Knight Pract. Dict. Mech. Suppl. Differential (Electricity), a coil of electrified wire having such relation to another electrified coil or to an armature (or needle) common to both as to produce polar action contrary to that produced by such other coil. (Electric Lamps), a conductor of high relative resistance—used with electric lamps in series,—which operates in the twofold capacity of shunting surplus current to the next lamp, and of shortening the arc of its own lamp, so as to maintain equal action in all lamps of the series. 1897 Electr. Age 3 July 10/1 The differentials secure a stable current when working on a part of the characteristic curve back of that where the heavy droop occurs. 4. a. A difference in the charges levied or prices charged for a particular type of thing. ΘΚΠ society > trade and finance > charges > [noun] > as determined by specific conditions rate1540 differential1879 1879 10th Ann. Rep. Board Railroad Commissioners (Mass.) 414 During that period the Central Vermont has operated under fixed differentials. 1890 Spectator 20 Sept. 383 The morality of American Railway Companies as regards..differentials and commissions. 1922 Colonial Tariff Policies (U.S. Tariff Comm.) i. 36 The term ‘free trade’ is frequently used loosely in reference to open-door régimes—that is, régimes whose characteristic feature is not absence of duties but absence of differentials. 1959 Punch 19 Aug. 30/2 The rise of Oundle's fees to £435 puts the school within £25 of Eton... What does Eton do now? Does it preserve its status by leaping ahead.., or does it get the Headmasters' Conference to negotiate a national agreement on differentials? 1965 New Statesman 23 Apr. 634/2 The major companies have reacted with countrywide cuts of 1d., 1½d. or 2d. off certain grades [of petrol]. Some..cut-price companies have followed suit, to try to keep their 3d. differential. 2008 L. Kaplow Theory Taxation & Public Econ. vi. 142 It is hardly obvious what sort of differentials in commodity taxation are justified on account of difficulties with income tax enforcement. 2009 Wall St. Jrnl. 2 June r6/2 The price differential between a feature phone and a smart phone has narrowed to the point where lots of people are migrating. b. A difference in wages between industries or between categories of employees in the same industry.Recorded earliest in wage differential n. at wage n. Compounds 3b; see also pay differential n. at pay n. Compounds 3. ΘΚΠ society > trade and finance > fees and taxes > payment for labour or service > wage structures and scales > [noun] > wage scale > relative grading of salaries > differential differential1894 wage differential1950 1894 Nation (N.Y.) 24 May 381/2 This series of wage differentials, as we may call it, has long been a matter requiring delicate treatment. 1941 Economist 8 Feb. 178/2 The present economic differentials between one occupation and another and one status and another are, over a wide field, calculated to make people stay where they are. 1955 Times 17 June 4/4 This trend would lift the skilled differential and the future might show a relative improvement in payment for skill. 2011 T. Brown-Nagin Courage to Dissent iv. 92 The judge held salary differentials between Atlanta's African-American and white teachers patently unconstitutional. 5. Biology. A distinguishing biological characteristic of an organism, species, etc.; a measure of to what degree a given organism or species differs (in some respect) from others. ΘΚΠ society > communication > indication > that which identifies or distinguishes > [noun] tokenc1000 distinctionc1374 differencea1398 signeta1425 knowledge?c1475 smell?a1505 markc1522 badge1529 note1583 impress1590 monument1590 type1595 stamp1600 pressure1604 mintage1612 criterion1613 impressa1628 differencer1633 lineament1638 mole1644 discrimination1646 tessera1647 diagnostic1651 monumental1657 discretive1660 signate1662 footmark1666 trait1752 memorandum1766 fingerprint1792 insignia1796 identifier1807 designative1824 cachet1840 differentiator1854 tanga1867 trademark1869 signature1873 totem1875 differential1883 earmarkings1888 paw print1894 discriminator1943 ident1952 1883 A. Hyatt in Proc. 32nd Meeting Amer. Assoc. Advancem. Sci. (1884) 358 During their subsequent history, characteristics are divisible into two categories: those which become morphological equivalents and are essentially similar in distinct series, and those which are essentially different in distinct series and may be classed as morphological differentials. 1913 Amer. Naturalist 47 36 One ought to be able to measure and correlate the differentials between organisms. 1953 Proc. National Acad. Sci. U.S.A. 39 128 In contrast to the organismal differentials which are the same in the different parts of an organism, we must distinguish the differentials of the various organs and tissues. 1988 T. G. Wolcott in W. W. Burggren & B. R. McMahon Biol. Land Crabs iii. 96 Controlled laboratory studies and field experiments will be needed to quantify differentials in requirements and exploitative abilities. 2011 C. C. Maley et al. in R. C. Fitzgerald Pre-Invasive Dis. vii. 115 The rate of clonal expansion depends on the relative fitness differential between a clone and its competitors. Compounds differential amplifier n. Electronics an amplifier which amplifies the difference between two inputs. ΚΠ 1922 Brit. Patent 174,312 3/1 The differential amplifiers will build up the vocal or telephonic current to audible value in the receiver. 1951 Electroencephalography & Clin. Neurophysiol. 3 497/1 The action potentials were preamplified in a differential amplifier. 2012 Power Electronics Technol. (Nexis) 26 July The ac line current is measured using the differential amplifier, U1, connected across the shunt resistor, R1. differential analyser n. now historical a device, typically an analogue computer, designed to solve differential equations. ΘΚΠ society > computing and information technology > hardware > computer > [noun] > analogue > differential analyser differential analyser1930 1930 Engin. Abstr. (Inst. Civil Engineers Great Brit.) No. 45. 33 (heading) An Alternating-Current Differential Analyser and its Application to Harmonic Analysis. 1957 Technology July 188/1 The analogue laboratory contains a large electro-mechanical differential analyser. 2006 D. Edgerton Shock of Old (2008) i. 7 Digital electronic computers were preceded by mechanical analogue computers, from tide predictors to differential analysers. differential calculus n. [after French calcul différentiel (1696 or earlier)] Mathematics the method of determining the tangent lines to curves through consideration of infinitesimally small changes of values (frequently with the); the branch of mathematics dealing with the properties of differentials and derivatives; cf. integral calculus at integral adj. 4b.In early use frequently with reference to the form of calculus developed by Leibniz, in contrast to that developed by Newton (cf. fluxional adj. 1). ΘΚΠ the world > relative properties > number > calculus > [noun] > differential calculus differential calculus1702 tetragonistic(al calculus1727 1702Differential Calculus [see sense A. 3]. 1790 Monthly Rev. 2 532 Having found, by means of the differential calculus, an equation of the radius osculator and amplitude of a curve..the author reduces it to co-ordinates. 1830 J. F. W. Herschel Prelim. Disc. Study Nat. Philos. iii. iii. 271 The method of fluxions, or, as it is now more generally called, the differential calculus. 1956 F. Bagemihl tr. K. Knopp Infinite Sequences & Series i. 17 We also assume that the reader is familiar..with the rudiments of differential calculus and function theory. 2007 N.Y. Times Mag. 30 Sept. 94 Most engineering schools stress subjects like differential calculus and physics. differential coefficient n. Mathematics a function which expresses the instantaneous rates of change of a given function at different points; = derivative n. 3. ΘΚΠ the world > relative properties > number > calculus > [noun] > differential calculus > differentiation > derivative derivativea1690 fluxion1704 differential coefficient1708 differential coefficient1786 first derivative1852 1786 C. Hutton Tracts Math. & Philos. iii. 38 The powers of the quantity..will then diverge faster than the differential coefficients converge. 1852 T. G. Hall Treat. Differential & Integral Calculus (ed. 5) iii. 31 This process is called successive differentiation, and du/dx, dp/dx, dq/dx, &c. are called the first, second, third, &c. differential coefficients, or the first, second, third, &c. derivatives of u. 1933 Proc. Sect. Sci. Kon. Akad. Wetensch. Amsterdam 36 152 The differential coefficients of G make a jump. 1993 J. O. Bird Higher Engin. Math. v. 35 The differential coefficient of a constant is zero. differential equation n. Mathematics an equation involving differentials or (now more commonly) derivatives.exact differential equation, partial differential equation: see the first element. ΚΠ 1704 C. Hayes Treat. Fluxions 151 We have this Differential Equation..which expresses the Nature of the Curve requir'd. 1895 Ann. Math. 9 65 Let us find the differential equations of the first order which are invariant. 2009 S. Blundell Superconductivity: Very Short Introd. vi. 73 They ended up with a pair of rather complicated differential equations. differential gear n. Mechanics an arrangement of gears that transmits equal power to each of a pair of wheels while allowing them to rotate at different speeds, used esp. in a motor vehicle to facilitate cornering. ΘΚΠ society > travel > means of travel > a conveyance > vehicle > vehicles according to means of motion > vehicle moving on wheels > [noun] > parts of vehicle moving on wheels > gear > differential gear differential gearing1842 differential gear1855 diff1912 society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear differential gearing1842 differential gear1855 differential1872 1855 Newton's London Jrnl. Arts & Sci. 1 340 Fig. 2, shews an arrangement of differential gear. 1938 J.-B. O. Sneeden Introd. Internal Combustion Engin. (new ed.) iv. 60 In 1927, the Citroën Gear Co. built a small oil engine with a single crankshaft and piston, but with a 2 to 1 differential gear between the connecting rod and the shaft. 2001 Automobile June 80/1 (advt.) We are gear cutters who specialise in making crownwheel & pinion sets & differential gears for all types of classic cars. differential gearing n. Mechanics gearing that involves a differential gear. ΘΚΠ society > travel > means of travel > a conveyance > vehicle > vehicles according to means of motion > vehicle moving on wheels > [noun] > parts of vehicle moving on wheels > gear > differential gear differential gearing1842 differential gear1855 diff1912 society > travel > means of travel > a conveyance > vehicle > powered vehicle > parts and equipment of motor vehicles > [noun] > transmission > shaft and joints transmitting drive > differential gear differential gearing1842 differential gear1855 differential1872 1842 J. B. F. Jouannin Brit. Patent 9415 (1855) 2 A machine composed of a clock and of a peculiar combination of wheelwork called by the Inventor differential gearing. 1918 Machinery Apr. 709/1 Differential gearing may be used to combine these drives and allow any variations in speed that may be required. 2003 P. R. Lord Handbk. Yarn Production vii. 169 The direction of lay is changed and so is the bobbin speed. This is usually accomplished by means of a pair of opposed cone pulleys and differential gearing. differential gene expression n. Genetics variation in the expression (expression n. 7) of particular genes by different cells. ΚΠ 1957 Bios 28 22 We must continue to explore them [sc. salivary-gland chromosomes] fully in our efforts to find a cytological basis for the differential expression of allelic genes.] 1963 Amer. Zoologist 3 134/1 Cellular differentiation is clearly a matter of differential gene expression. 1986 Jrnl. Molecular Biol. 191 431/1 Whether the regulation of this differential gene expression is exerted at the transcriptional or post-transcriptional level remains to be determined. 2001 New Scientist 16 June 90 (advt.) Research Assistant... Required for two years..to work on an exciting parasitology project funded by the Home of Rest for Horses, to study differential gene expression in cyathostomins. differential geometry n. [after French géometrie différentielle (1854 in the passage translated in quot. 1877)] Mathematics the branch of mathematics concerned with the study of geometry by means of techniques from calculus. ΘΚΠ the world > relative properties > number > geometry > [noun] > branches of planimetrya1393 conic?a1560 helicosophy1570 stereometry1570 spheric1660 planometry1669 mensuration1704 polygonometry1791 analytical geometry1802 isoperimetry1811 analytic geometry1817 algebraic geometry1821 coordinate geometry1837 non-Euclidean geometry1872 differential geometry1877 pangeometry1878 projective geometry1878 metageometry1890 Riemann geometry1895 variable geometry1957 1877 R. Congreve tr. A. Comte Syst. Positive Polity IV. iii. 177 Seven chapters will put into their proper shape the calculus..; preliminary geometry; algebraic geometry; differential geometry; integral geometry; and general mechanics. 1960 Tucson (Arizona) Daily Citizen 18 Feb. 39/1 The first universe-shaking idea that arose from differential geometry is that space is curved. 2010 G. G. Szpiro Math. Medley xix. 96 After formulating the theory of special relativity in 1905, Einstein spent the following decade intensively studying differential geometry. differential GPS n. a form of GPS (GPS n. at G n. Initialisms) in which extremely accurate results are obtained by comparing the known positions of fixed ground stations with the same positions indicated by satellite. ΚΠ 1981–2 Navigation Winter 353 Several of these applications are presented, including angle determination, single-channel differential GPS, area navigation and precision approach. 1992 In-Fisherman Feb. 48/2 After having spent millions on the SA-on/off system, an add-on called Differential GPS is rumored. 1998 Sunday Capital (Annapolis, Maryland) 22 Feb. c11/1 Coast Guard continually utilizes differential GPS to confirm positions. differential lock n. Mechanics a device which disables the differential gear of a motor vehicle, forcing each of a pair of wheels to turn at the same speed; cf. diff lock n. at diff n.³ Compounds.A differential lock can be advantageous in maintaining traction, e.g. at high speed or on muddy or loose terrain. ΚΠ 1914 Pop. Mech. Mar. 373/1 There is a differential lock by which the full tractive effort may be thrown on both rear wheels whenever necessary. 1988 Road & Track Nov. 93/1 Apparently BMW's automatically engaging viscous differential locks in the center and rear really get the job done. 2002 H. Heisler Adv. Vehicle Technol. (ed. 2) vii. 235/1 The differential lock has to be engaged manually by cable or compressed air. differential psychology n. [after German differentielle Psychologie (1900 in the subtitle of a work by William Stern)] the scientific study of the differences between individuals in their thinking and behaviour. ΚΠ 1900 Monist 11 140 Differential psychology studies, first individual differences per se, secondly their conditions and causes, and thirdly their forms of expression. 1958 A. C. Tolman Behavior & Psychol. Man p. viii The importance of differential psychology is now accepted so much as a matter of course that one is likely to forget that around 1920 the really dignified and important psychology was experimental. 2012 N.Y. Times (National ed.) 2 Nov. b13/1 Differential psychology, a field whose central question—What makes people behave and think differently from one another?—strikes at the heart of the age-old nature-nurture debate. differential pulley n. Mechanics a pulley having a block with two rigidly connected wheels or sheaves of different diameters, the chain or rope unwinding from one as it winds on to the other. ΘΚΠ society > occupation and work > equipment > lifting or hoisting equipment > [noun] > tackle > pulley > types of ram-head1611 pentaspast1702 differential pulley1833 jackanapes1844 well pulley1855 brake-pulley1873 1833 Repertory Patent Inventions 16 74 My [sc. J. Saxton's] invention consists in the application of pulleys of different diameters, which I denominate, ‘The differential Pulleys’. 1917 H. S. Carhart & H. N. Chute Physics with Applic. vi. 168 A practical advantage of the differential pulley is that there is always enough friction to keep the weight from dropping. 2009 O. A. Bauchau & J. I. Craig Struct. Anal. ix. 418 The mechanical advantage of the differential pulley increases as radii r_i and r₀ approach equal values. differential scanning calorimeter n. an instrument for performing differential scanning calorimetry. ΚΠ 1963 Jrnl. Sci. Instr. 40 470/2 Differential scanning calorimeter DSC-1. Perkin-Elmer Ltd... The DSC-1 measures the difference of electrical power required to maintain sample and reference materials at the same temperature while the temperature is varied. 1990 Omni July 97/3 With a differential scanning calorimeter,..a high-resolution optical microscope, and an advanced gas analyzer,..Rover is a rolling laboratory, capable of finding any carbonic remains or soil microbes. 2012 C. Ratti in J. Ahmed & S. Rahman Handbk. Food Process Design I. xxii. 632 The differential scanning calorimeter and freeze-drying microscope are two specialized techniques for determining important product properties related to freeze-drying. differential scanning calorimetry n. a method of measuring the difference between the amounts of heat needed to increase the temperatures of a sample and a reference when the temperatures of both are changed in step with one another; abbreviated DSC.The principle behind differential scanning calorimetry is that when a sample undergoes a physical transformation as the temperature is varied, a different amount of heat will need to flow to it than to the reference to maintain both at equal temperatures. It can be used to measure various characteristic properties of a sample, including physical changes (as crystallization or melting) and chemical ones (as oxidation); it is also used as a quality control procedure. ΚΠ 1965 Talanta 12 p. vii General Applications of Differential Scanning Calorimetry. A. P. Gray. 1990 Y. Doi Microbial Polyesters vii. 118 The crystallization and melting temperature..have been studied by the thermal analysis of differential scanning calorimetry (DSC) thermograms. 2009 Food Chem. 116 137 Differential scanning calorimetry was used to analyze gelatinization and retrogradation of waxy rice starch. differential screw n. Mechanics a screw having two threads of different pitch in different parts of its length.The two threads might be of differing handedness (so that one unwinds as the other winds), or they may be of slightly different pitch (so as to generate small accurate movements corresponding to the difference of the pitches). ΚΠ 1824 London Mechanics' Reg. 25 Dec. 114/1 (heading) The Differential Screw, invented by Mr. Perkins. 1916 Pop. Sci. Mar. 460 This differential screw consists of a combination of an 8-32 screw and a 2-56 screw. 2008 P. R. Yoder Mounting Optics Optical Instruments (ed. 2) ix. 386 Differential screws might be employed to advantage as the means for attaching the fixed ends of the tangent arms to the brackets. differential thermometer n. a thermometer for measuring small changes or differences in temperature rather than actual temperature.The Beckmann thermometer, invented in 1905, is a common type of differential thermometer. ΘΚΠ the world > matter > properties of materials > temperature > measurement of temperature > [noun] > instrument > for detecting minute differences differential thermometer1804 thermoscope1804 1804Differential thermometer [see sense A. 2c]. 1923 Ecology 4 189 The instrument consists of a differential thermometer in a vacuum tube, which is connected with a recording apparatus. 2010 K. W. Whitten et al. Chemistry (ed. 9) xiv. 523 Specially constructed differential thermometers..measure small temperature changes accurately to the nearest 0.001°C. differential tone n. [after German Differenzton (see difference tone n. at difference n.¹ Compounds)] Acoustics and Music a tone sometimes perceived during the simultaneous sounding of two other tones, its frequency being the difference between those of the tones being played; = difference tone n. at difference n.¹ Compounds; cf. summational tone at tone n. 2a(a). ΚΠ 1864 A. J. Ellis in Proc. Royal Soc. 1863–4 13 393 The pitch of the principal and only one of these combinational tones necessary to be considered, is the difference of the pitch of its generating tones. It will therefore be termed the differential tone. 1908 E. H. Barton Text-bk. Sound vii. 384 To hear a differential tone, the generators should be high in pitch and preferably near together. 2005 M. Segell Devil's Horn (2006) ix. 192 François had studied the nature of differential tones, which are produced by two different notes sounding at once. differential winding n. Electrical Engineering (in some electromagnets, galvanometers, transformers, etc.) a winding (winding n.¹ 8b) that is in the opposite direction to another (typically adjacent) winding, or that produces an effect that counters that of the other winding. ΚΠ 1882 Official Gaz. (U.S. Patent Office) 28 Feb. 585/2 A local relay having a double set of differential windings or helices which form parts of local circuits. 1922 D. C. Jackson & J. P. Jackson Alternating Currents & Alternating Current Machinery (new ed.) xi. 656 The relay C consists of a U-shaped magnet core carrying a differential winding and provided with a pivoted armature which controls a circuit contact. 1992 S. H. Horowitz & A. G. Phadke Power Syst. Relaying viii. 205 Very small currents flow in the differential windings of the three relays during normal conditions. This entry has been updated (OED Third Edition, March 2016; most recently modified version published online June 2022). < adj.n.1615
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