periphracticadj.

Brit.

/ˌpɛrᵻˈfraktɪk/, U.S.

/ˌpɛrəˈfræktɪk/

Origin: A borrowing from German. Etymon: German periphraktisch.

Etymology: < German periphraktisch (J. B. Listing 1862, in Abhandlungen der mathematischen Classe der Königlichen Gesellschaft der Wissenschaften zu Göttingen 10 135) < Hellenistic Greek περίϕρακτος fenced round (recorded in (neuter) noun use, περίϕρακτον enclosure; < ancient Greek περι- peri- prefix + Hellenistic Greek ϕρακτός fenced, protected ( < the stem of ancient Greek ϕράσσειν (Attic ϕράττειν ) to fence in (see phragma n.) + -τός , suffix forming verbal adjectives), after περιϕράσσειν to fence, fortify all round) + German -isch -ish suffix¹; see -ic suffix. Compare periphraxy n.

Geometry.

1. Designating a region of space having one or more internal bounding surfaces (or curves, when the region is two-dimensional) unconnected with the external boundary (e.g. a globe with an internal cavity, or an annulus), so that a closed surface (or curve, when the region is two-dimensional) may be drawn within the region which cannot be contracted to a point without passing out of the region. Cf. cyclic region at cyclic adj. 5.

ΘΚΠ

the world > relative properties > number > geometry > shape or figure > [adjective] > having specific property

hypotenusal?a1560

oblique?a1560

local1673

focal1676

octantal1777

symmetrical1794

radical1848

self-conjugate1855

quadric1856

stellated1859

periphractic1881

homoeoidal1883

tridiametral1891

one-sided1893

semi-infinite1903

simplicial1913

mirror-symmetric1952

1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 17 When a region encloses within itself other regions, it is called a Periphractic region.

1895 H. Lamb Hydrodynamics 43 Let us suppose that the region occupied by the irrotationally moving fluid is periphractic, i.e. that it is limited internally by one or more closed surfaces.

1970 Jrnl. Appl. Math. 19 243 We obtain..a linear combination of specific biharmonic functions, the number of which depends upon the degree to which the domain is periphractic.

1992 Jrnl. Fluid Mech. 245 29 Progressive radial cross-waves in a deep, periphractic wavetank are investigated on the assumption that the vertical component of the capillary force vanishes at the wavemaker.

†2. In extended use: designating the number of independent internal boundaries in such a region. Obsolete. rare.

ΚΠ

1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 23 The whole number of lines to be drawn to remove the periphraxy is equal to the periphractic number or the number of internal surfaces.

This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022).

单词	periphractic
释义	periphracticadj. Brit. /ˌpɛrᵻˈfraktɪk/, U.S. /ˌpɛrəˈfræktɪk/ Origin: A borrowing from German. Etymon: German periphraktisch. Etymology: < German periphraktisch (J. B. Listing 1862, in Abhandlungen der mathematischen Classe der Königlichen Gesellschaft der Wissenschaften zu Göttingen 10 135) < Hellenistic Greek περίϕρακτος fenced round (recorded in (neuter) noun use, περίϕρακτον enclosure; < ancient Greek περι- peri- prefix + Hellenistic Greek ϕρακτός fenced, protected ( < the stem of ancient Greek ϕράσσειν (Attic ϕράττειν ) to fence in (see phragma n.) + -τός , suffix forming verbal adjectives), after περιϕράσσειν to fence, fortify all round) + German -isch -ish suffix¹; see -ic suffix. Compare periphraxy n. Geometry. 1. Designating a region of space having one or more internal bounding surfaces (or curves, when the region is two-dimensional) unconnected with the external boundary (e.g. a globe with an internal cavity, or an annulus), so that a closed surface (or curve, when the region is two-dimensional) may be drawn within the region which cannot be contracted to a point without passing out of the region. Cf. cyclic region at cyclic adj. 5. ΘΚΠ the world > relative properties > number > geometry > shape or figure > [adjective] > having specific property hypotenusal?a1560 oblique?a1560 local1673 focal1676 octantal1777 symmetrical1794 radical1848 self-conjugate1855 quadric1856 stellated1859 periphractic1881 homoeoidal1883 tridiametral1891 one-sided1893 semi-infinite1903 simplicial1913 mirror-symmetric1952 1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 17 When a region encloses within itself other regions, it is called a Periphractic region. 1895 H. Lamb Hydrodynamics 43 Let us suppose that the region occupied by the irrotationally moving fluid is periphractic, i.e. that it is limited internally by one or more closed surfaces. 1970 Jrnl. Appl. Math. 19 243 We obtain..a linear combination of specific biharmonic functions, the number of which depends upon the degree to which the domain is periphractic. 1992 Jrnl. Fluid Mech. 245 29 Progressive radial cross-waves in a deep, periphractic wavetank are investigated on the assumption that the vertical component of the capillary force vanishes at the wavemaker. †2. In extended use: designating the number of independent internal boundaries in such a region. Obsolete. rare. ΚΠ 1881 J. C. Maxwell Treat. Electr. & Magnetism (ed. 2) I. 23 The whole number of lines to be drawn to remove the periphraxy is equal to the periphractic number or the number of internal surfaces. This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022). < adj.1881
随便看	psephology psephomancy psettaceous psettine pseud pseud'pseuds' corner pseud's corner pseud-amoeboid pseudaconitia pseudaconitine pseudaesthesia pseudambulacral pseudambulacrum pseudamoeboid pseudandry pseudaphia pseudaposematic pseudapostolical pseudarachnidan pseudarthrosis pseudataxic pseudaxine pseudechic pseudechis pseudelephant