| 释义 |
▪ I. pivot, n.|ˈpɪvət|
Also 7 pivat, 8 pevot, pevet(t.
[a. F. pivot (12th c. in Hatz.-Darm.) pivot, hinge. Origin obscure. Cf. mod. Prov. pivo a pointed thing (?), It. piviolo, pivolo wooden peg or pin, dibble, penis, etc., perhaps related to It. piva pipe.]
1. a. A short shaft or pin, usually of metal and pointed, forming the fulcrum and centre on which something turns or oscillates; as the pin of a hinge, the end of an axle or spindle, or the arbor on which the hands of a timepiece turn; a pintle, gudgeon.
1611Cotgr., Pivot, the piuot, or (as some call it) the Tampin of a gate, or great doore. 1685Boyle Enq. Notion Nat. 305 The excited Magnetick Needle, and the Box that holds It, are duly pois'd by Means of a competent number of opposite Pivats. 1704J. Harris Lex. Techn. I, Pevetts, are the Ends of the Spindle of any Wheel in a Watch; and the Holes into which they run, are called Pevett-holes. 1763Phil. Trans. LIII. 143 The gudgeons, or pevets, in large engines, are seldom turned true. 1805Brewster in Ferguson's Lect. I. 82 note, The extremities of an axle or spindle,..are called gudgeons when the wheels are large, and pivots in small pieces of machinery. 1872Mivart Elem. Anat. 31 The atlas vertebra is formed to turn on the odontoid process of the axis as on a pivot.
†b. A dowel or toggle. Obs. rare.
1730A. Gordon Maffei's Amphith. 213 The Stones..are..clasped at the Top of the Arches with Pivots or Nails.
2. Mil. The officer or man on whom a body of troops wheels; also that flank by which the alignment or dressing is corrected. fixed pivot, movable pivot: see quot. 1832.
1796Instr. & Reg. Cavalry (1813) 37 When the squadron has wheeled to a flank by divisions.—If to the right, then the left officer is on the pivot of the rear division, and the right officer shifts to the pivot of the front division. 1832Regul. Instr. Cavalry iii. 47 Pivot, the outward man on that flank of a Squadron or smaller body upon which that body turns in wheeling... Fixed Pivot, is when the flank man during a wheel turns upon his own ground. Moveable Pivot, is when the flank man during a wheel describes a portion of a circle. 1859F. A. Griffiths Artil. Man. (1862) 141 A battery can..change front on a moveable pivot by a simple wheel. 1860Vol. Cav. Movem. in Blackw. Mag. Mar. 371/1 ‘When Right is in front, Left is the Pivot.’ This is the first thing taught to the Cornet.
3. transf. and fig.
a. That on which anything turns; a cardinal or central point.
1813Examiner 17 May 312/2 His Majesty..waited the moment.., to put in motion..his army.., make a pivot on Leipzic. 1818Cobbett Pol. Reg. XXXIII. 594 The paper-money is the pivot, on which their all turns. 1878Simpson Sch. Shaks. I. 122 Those questions of right which between Christians would be the chief pivots of the decision. 1888Bryce Amer. Commw. II. xliv. 151 In all States, the Governor..may at any moment become the pivot on whose action public order turns.
b. spec. A device in Japanese poetry: see quots., and cf. pillow-word s.v. pillow n. 6.
1877B. H. Chamberlain in Trans. Asiat. Soc. Japan V. 86 A more complicated species of pun, occurring when a word with two meanings is used only once as a sort of pivot on which two wheels turn. In this case, the first part of the poetical phrase has no logical end, and the latter part no logical beginning... An example of what might be termed pivot-puns. 1880― Class. Poetry Japanese Introd. 4 The ‘Pivot’ is a more complicated device, and one which, in any European language, would be not only insupportable, but impossible, resting, as it does, on a most peculiar kind of jeu de mots.
c. In football and some other games, a player in a central position, esp. a centre-back; such a position. Also attrib.
1911Hartley Coll. Mag. XII. xxxiii. 48 Howarth was moved from outside left to centre, but it was obvious..he would be spoilt if retained as pivot. 1928Weekly Dispatch 24 June 21/7 Robert Plenderleith, the East Fife centre half-back, one of the most promising of young pivots in Scotland. 1930Daily Express 6 Oct. 16/5 Wilson, the Huddersfield pivot, was kept mainly on the defensive. 1951Football Record (Melbourne) 8 Sept. 13 The Dons' hopes of success could well depend on his ability to gain control of the pivot position today. 1970Globe & Mail (Toronto) 26 Sept. 36/2 Winnipeg has been looking for a take-charge pivot after going through a disappointing season. 1974State (Columbia, S. Carolina) 27 Feb. 2-b/4 Jim Bolla, 6–8, is expected to be in the pivot. 1974Plain Dealer (Cleveland, Ohio) 26 Oct. 4-d/1 In the pivot Steve Patterson and Jim Chones totalled 13 boards. 1975Oxf. Compan. Sports 66/1 The tallest players of all, playing near the basket, are called pivots, centres, or posts. 1976Sunday Tel. 25 Jan. 36/2 There is emerging a new nomenclature which refers to the ‘pivot five’, those players in the back row of the scrum and at half-back whose talent and technique decide how the ball is used at source.
d. = pivotal man s.v. pivotal a. 1 b.
1919Punch 29 Jan. 76/2 They are keeping all the pivots in this area for one final orgy of demobilisation at some future date.
e. Math. In the numerical evaluation of a determinant, or the numerical solution of simultaneous linear equations, a non-zero element of the determinant or matrix which is used as follows: all elements in its row are divided by it, and appropriate multiples of that row are then subtracted successively from the other rows, so that the pivot itself is replaced by unity and all other elements in its column are replaced by zero; (this gives, in the case of a determinant, a number, the pivot, multiplied by a determinant whose order is reduced by one, and in the case of simultaneous equations, a set of equations one fewer in number from which one of the variables has been eliminated). Freq. attrib.
1933Proc. Edin. Math. Soc. III. 211 At Stage II we choose another pivot at will..and cross-multiply with respect to it in the same way, dividing each result, however, by the previous pivot, 5. 1940Brit. Jrnl. Psychol. XXX. 363 The determinant is condensed in the manner already shown (each pivot being converted into unity) until it is reduced to one number. 1958S. I. Gass Linear Programming ii. 29 Since at the start of an iteration it is convenient to make the coefficient of the variable being eliminated equal to 1, we divide the second equation by 3. The coefficient 3 is referred to as the pivot element. Ibid. iv. 58 Element Xlk is the pivot element of the elimination transformation, with row l being the pivot row and row [read column] k being the pivot column. 1971Coulson & Richardson Chem. Engin. III. iv. 295 Some methods of solution are better adapted to automatic digital computers than others. The method of Gaussian elimination with selection of pivots, or pivotal condensation, is particularly suitable. 1973Phillips & Taylor Theory & Appl. Numerical Anal. viii. 197 The fault in the first attempt at solving Example 8.6 was that a small pivot (the coefficient of x in the first equation), meant that very large multiples of the first equation were added to the others, which were therefore ‘swamped’ by the first equation, after rounding.
f. Linguistics. = pivot word.
1963M. D. S. Braine in Language XXXIX. 4 There is a basis for defining two primitive word classes: a class of pivots..to which a few frequently occurring words belong, and a complementary class which has many members, few of which recur in more than one or two different combinations. 1966D. McNeill in Smith & Miller Genesis of Lang. 21 It never happens..that two⁓word sentences are made up only of pivots. 1971Jrnl. Speech & Hearing Disorders XXXVI. 44 Rules that account for utterances in terms of the juxtaposition of pivots and open words cannot account for differences in semantic interpretation. 1973M. F. Bowerman Early Syntactic Devel. 30 Students of language acquisition have sometimes referred to words which a child uses with greater-than-average frequency as ‘pivots’... When used in this way, the conception of ‘pivot’ has little more relevance to child speech than to adult speech. 1975Canad. Jrnl. Linguistics XX. 220 Arabic children have a much easier time of it than English children since such Pivot—Open constructions are generally well-formed sentences in adult grammar.
†4. Gardening. (See quot., and cf. pivot v. 3.)
1725Bradley Fam. Dict. s.v. Tree, If the lower or bottom part of the Stem be..thicker than all the rest, it ought ever to preserve it self in that State; but if..it continues smaller than some part a little above it, from whence in effect some fine Roots proceed; then..you must entirely cut off this smaller Part, with all its Appurtenances: Many Gardiners call it Pivot, and those Roots must only be preserv'd that proceed from the fortunate Part.
†5. The nipple of a percussion-lock. Obs.
1835Encycl. Brit. (ed. 7) XI. 39/1 The next peculiarity of the ordinary detonating lock is the pivot or nipple. 1836T. Oakleigh Oakleigh Shooting Code 18 The pivot is the nipple or cone of iron screwed into the breach, and on which the copper cap is placed.
6. attrib. and Comb.
a. appositive or adj. That is the pivot on which something turns or depends; cardinal; pivotal.
1861E. Garbett Boyle Lect. 247 Heathenism fixed itself upon these pivot qualities of the heart. 1875Poste Gaius i. Introd. (ed. 2) 2 Some of the pivot terms and most pervading conceptions.
b. Comb., as pivot-file (file n.1), pivot-gauge, pivot-hole, pivot-lathe, pivot-pin, pivot-point, pivot-polisher; (in sense 2) pivot file (file n.2), pivot flank, pivot leader, pivot man, pivot manœuvre, pivot officer, pivot ship; pivot bearing = footstep 5 d; pivot-bolt, a central pintle about which a pivot-gun oscillates horizontally; pivot break Rugby Football (see quot.); pivot-bridge, a swing bridge pivoted on a central pier; pivot-broach, a watchmaker's tool; pivot class Linguistics, the class of pivot words; pivot-drill = pivot-broach; pivot-frame, a frame turning on a pivot, so that the gun it carries may be pointed in any direction; pivot-gearing, gearing for allowing the axis of a driving wheel to be shifted, so as to communicate power in various directions; pivot grammar Linguistics, a grammar of an early stage in children's speech in which two word classes are postulated, pivot words (see below) and a larger open class; pivot-gun (see quots.); pivot-joint Anat., a joint in which the articular movement is that of a pivot; pivot pass Rugby Football (see quot.); pivot-pricker, a slender pointed instrument for clearing the nipple of a percussion-lock; pivot-pun (see 3 b); pivot-span, that span of a bridge which turns or opens on a pivot; pivot-tooth (see quot. 1875); pivot-transom, the front member of the chassis of a casemate gun; pivot word Linguistics, one of a limited set of words recurring in particular utterance positions at an early stage of a child's acquisition of syntax, and postulated as constituting one of two basic word classes at this stage of development; pivot-wrench, a small turning tool for securing or loosening the nipple of a percussion-lock to and from the barrel; now called nipple or cone-wrench.
[1875Engineering 30 July 87/1 Pivoted bearings for line shafts, now almost universally employed in America.] 1877W. C. Unwin Elem. Machine Design vii. 122 (heading) *Pivot and collar bearings. 1960V. B. Guthrie Petroleum Products Handbk. ii. 29 Oils used for pivot bearings in instruments are of low volatility. 1975Sci. Amer. July 50/3 If a combination of the two forces exists, a special bearing (an angular bearing, a taper bearing or a pivot bearing) is employed.
1875Knight Dict. Mech., *Pivot-bolt.
1960E. S. & W. J. Higham High Speed Rugby 70 Another way..is to break on the side of the scrum on which the ball was put in. This is sometimes called the ‘*pivot’ break, because the scrum⁓half pivots around his outside foot.
1875Knight Dict. Mech. 1721/2 A *pivot-bridge of the New York Central Railway on the Linville principle.
Ibid., *Pivot-broach, a..tool for opening the pivot-holes of watches.
1964Amer. Psychologist XIX. 3/2 Two classes of words appear—a *pivot class and an open class—and the child launches forth on his career in combinatorial talking. 1966D. McNeill in Smith & Miller Genesis of Lang. 20 The pivot class characteristically has few members compared with the open class. 1970― Acquisition of Lang. iii. 25 Pivot classes may appear first or second in sentences.
1833Regul. Instr. Cavalry i. 38 The *pivot files..face to the left. 1884F. J. Britten Watch & Clockm. 199 Pivot File..[is] a file used for forming pivots.
1833Regul. Instr. Cavalry i. 38 They resume their places on the *pivot flank.
1858Greener Gunnery 131 The piece..is mounted upon a carriage..which embraces a *pivot frame and recoil slide.
1884F. J. Britten Watch & Clockm. 199 *Pivot Gauge,..a steel plate with tapered slit used for measuring pivots.
1970L. M. Bloom Lang. Devel. 24 The speech of children described in *pivot grammars in other investigations. 1971Jrnl. Speech & Hearing Disorders XXXVI. 42 How does pivot grammar relate to the grammar of the adult model language? Ibid. 47 The notion of pivot grammar describes children's early speech in only the most superficial way. 1973M. F. Bowerman Early Syntactic Devel. 4 An analysis of diary studies of children acquiring languages other than English led Slobin..to hypothesize that the pivot grammar might be a universal first grammar regardless of the particular language being acquired. 1976Word 1971 XXVII. 33 In what ways does mother-child interchange indicate that Laura's initial two-word combinations are semantically and structurally too sophisticated to be described adequately by a pivot grammar?
1858Simmonds Dict. Trade, *Pivot-gun, a piece of ordnance turning freely on a pivot, to alter the direction. 1859F. A. Griffiths Artil. Man. (1862) 150 Markers mark for the pivot guns of half batteries. 1704*Pivot-hole [see sense 1].
1872Huxley Phys. vii. 171 The second kind of *pivot-joint is seen in the forearm. 1881Mivart Cat 122.
1796Instr. & Reg. Cavalry (1813) 17 The *pivot leader..will begin in his own person to circle behind the line from the old, so as to enter the new direction twenty or thirty yards from the point of intersection.
a1814Manœuvring iii. i. in New Brit. Theatre II. 101 Ever since..you have been our lady's *pivot-man: every thing turns on you. 1847Infantry Man. (1854) 15 Those nearest the pivot man making their steps extremely small. 1918Daily Mail 6 Dec. 3/3 (heading) 12,000 pivot men. 1967Boston Sunday Herald 9 Apr. (This Week Mag.) 4/3 Locate the ‘pivot man’ on each team—he's the fielder who makes the first move as the team adjusts position for each new batter. 1971L. Koppett N.Y. Times Guide Spectator Sports iii. 88 The pivotman is usually the center, and the tallest man on his team. 1978Detroit Free Press 5 Mar. c. 4/2 Joe Barry Carroll, Purdue's 7–1 pivotman, scored 14 of his game high 22 points in the first half.
1796Instr. & Reg. Cavalry (1813) 43 In movements in column, the *pivot officers..are answerable for covering, and for proper wheeling distances.
1960E. S. & W. J. Higham High Speed Rugby 68 You will have to pivot round on the outside foot as you take off. This is called the ‘*pivot’ or ‘reverse’ pass.
1884Mil. Engineering (ed. 3) I. ii. 58 A plate round the point or thin end, with a hole for the *pivot pin.
1836T. Oakleigh Oakleigh Shooting Code 106 Articles necessary to the grouse-shooter's equipment..; fowling-piece, in case or bag; two extra pivots; a *pivot-pricker; pivot-wrench.
1867Smyth Sailor's Word-bk., *Pivot-ship, in certain fleet evolutions, the sternmost ship remains stationary, as a pivot on which the other vessels are to form the line anew.
1872L. P. Meredith Teeth (1878) 138 The six front roots above and below..are the only ones upon which it is advisable to ingraft *pivot teeth. 1875Knight Dict. Mech., Pivot-tooth,..an artificial crown attached to the root of a natural tooth by a dowel-pin of wood or metal occupying the nerve-canal.
Ibid. 1721/2 A traversing platform passing through the *pivot transom and the front sleeper of the platform.
1963M. D. S. Braine in Language XXXIX. 4 These words will be called ‘*pivot’ words, since the bulk of the word combinations appear to be formed by using them as pivots to which other words are attached as required. 1964Amer. Psychologist XIX. 3/2 Whereas before, lexemes like allgone and mummy and sticky and bye-bye were used singly, now, for example, allgone becomes a pivot word and is used in combination. 1966D. McNeill in Smith & Miller Genesis of Lang. 20 Each pivot word is used more frequently than individual open-class words. 1975Canad. Jrnl. Linguistics XX. ii. 220 Much has been made in studies of children's syntax in English of a stage at which there are only two parts of speech, a Pivot, or function word like ‘want’, and an Open, or content word like ‘milk’.
1836*Pivot-wrench [see pivot-pricker].
Senses 3 e, f in Dict. become 3 f, g. Add: [3.] e. Basketball. A movement in which the player holding the ball may take one or more paces in any direction with one foot, while keeping the other (the pivot foot) in fixed contact with the floor.
1920Frost & Wardlaw Basket Ball & Indoor Baseball for Women iv. 27 The pivot may be taken on the ball or heel of the foot, but the foot must remain in place. 1929H. C. Carlson Your Basket Ball v. 88 In the pivot and return pass no. 2 is automatically between no. 1 and his opponent. 1941J. Naismith Basketball 66 Closely allied with the dribble is the pivot. 1954Basketball (‘Know the Game’ Ser.) (rev. ed.) 12/1 The pivot foot may be lifted to pass or shoot provided the ball is released before the foot touches the ground again. 1982N.Y. Times 5 Apr. c9/4 How many steps is he allowed to take before a pivot foot must be established for the next attempted throw?
▪ II. ˈpivot, v.
[a. F. pivoter, f. pivot: see prec.]
1. trans. To furnish with, mount on, or attach by means of, a pivot or pivots. (Chiefly in passive.)
1855Hyde Clarke Dict. 292/2 Pivot, place on a pivot. 1869E. J. Reed Shipbuild. xx. 454 To have the model pivoted at the ends. 1879G. B. Prescott Sp. Telephone p. ii, An electro-magnetic telegraph..the armature of which was pivoted so as to vibrate between its poles. 1882Nares Seamanship (ed. 6) 192 If yards were pivoted in the centre of the mast.
b. fig.: cf. prec. 3. (In quot. 1851, to serve as a pivot to.)
1851Fraser's Mag. XLIV. 472 There is not a man..whose moral and mental centre of gravity more firmly pivot the violent oscillations and gyrations of his ‘passionate’ energy. 1878R. H. Hutton Scott x. 101 Scott's romances..are pivoted on public rather than mere private interests.
2. intr. To turn as on a pivot; to hinge; in military manœuvres, to swing round a point as centre. Chiefly fig.
1841Lever C. O'Malley xc, The 7th took up their ground at Frenada pivoting upon the 1st Division. 1872H. W. Beecher in Chr. World Pulpit II. 250 You know that Christ's ministry was pivoting upon Capernaum. 1883Holme Lee Loving & Serving II. ix. 154 ‘No’, said the clergyman, and pivoted on his heel. 1892Pictorial World 11 June 52/1 The entire question pivots on Ulster.
3. Gardening. (See quot., and cf. pivot n. 4.)
1895Syd. Soc. Lex. s.v., In Bot., a main root which grows vertically downwards is spoken of as ‘pivoting’ (Littré).
Hence ˈpivoted ppl. a., ˈpivoting ppl. a.
1855Hyde Clarke Dict. 292/2 Pivoted, a. 1870Daily News 27 July 5 This bridge is built in three portions, the centre resting upon four piers, and a pivotted portion of either end of about thirty yards in length. 1875Dental Cosmos XVII. 511, I removed the pivoted root [of a tooth], which was covered by a tumid and dark purple gum. 1882Nares Seamanship (ed. 6) 244 The..frames carry pivoted screw nuts. 1888Pall Mall G. 16 May 9/1 The eye of the bracket which receives the pivoting pin. |