Forms: 4–5 sentre, 6 centur, (centure, centrie, centry), 6– center, 4– centre. [a. F. centre (It., Sp. centro), ad. L. centr-um: see CENTRUM below.
The prevalent spelling from 16th to 18th c. was center, in Shakespeare, Milton, Boyle, Pope, Addison, etc.; so the early dictionaries, Cotgr. (‘centre, F., a center’), Cockeram, Phillips, Kersey, and all the thirty editions of Bailey, 1721–1802; but the technical volume of Bailey (Vol. II.) 1727–31, and the folio 1730–36, have centre; ‘an interleaved copy of the folio of 1730 was the foundation of Johnson’s Dictionary,’ which followed it in spelling centre; this has been generally adopted in Great Britain, while center is the prevalent spelling in the United States.
I. The center of a circle, of revolution, of centripetal attraction; and connected uses.
1. The point round which a circle is described; the middle point of a circle or sphere, equally distant from all points on the circumference.
c. 1374. Chaucer, Boeth., IV. v. 132. Þe sterres of arctour ytourned neye to þe souereyne centre or point. Ibid. (c. 1391), Astrol., I. § 4.
c. 1400. Maundev., xvii. 185. Aboute the poynt of the gret Compas, that is clept the Centre … Alle the Lynes meeten at the Centre.
1413. Lydg., Pylgr. Sowle, I. iii. (1483), 4. The Centre of the erthe was wonder derck.
1570. Billingsley, Euclid, XI. xiv. 316. The centre of a Sphere is that poynt which is also the centre of the semicircle.
1591. Morley, Introd. Mus., 18. His signe is a whole cirkle with a prick or point in the center or middle, thus ☉.
1613. R. C., Table Alph. (ed. 3), Centre, middest of any round thing or circle.
1651. Hobbes, Leviath., IV. xlvi. 375. The centre of the Earth is the place of Rest.
1683. Salmon, Doron Med., I. 91. From the Center to the Circumference.
1774. M. Mackenzie, Maritime Surv., 23. The Lines … will intersect each other in … the Center of the Circle.
1822. Imison, Sc. & Art, I. 15. They are all drawn towards the center of the earth.
1868. Lockyer, Elem. Astron., vii. xli. 239. A circle is a figure bounded by a curved line, all the points in which are the same distance from a point within the circle called the centre.
b. fig.
c. 1600. Shaks., Sonn., cxlvi. Poore soule the center of my sinfull earth.
a. 1631. Donne, Poems (1650), 7. This bed thy center is, these wals thy spheare.
1836. Emerson, Nature, v. Wks. (Bohn), II. 157. The moral law lies at the centre of nature, and radiates to the circumference.
2. ellipt. a. The center of the earth.
138[?]. Wyclif, Serm., Sel. Wks. I. 356. As þe sentre is lowest of alle þingis.
1602. Shaks., Ham., II. ii. 159. I will finde Where truth is hid, though it were hid indeede Within the Center.
1611. Tourneur, Ath. Trag., IV. iii. I will search the Center but Ile find out the murderer.
1823. Lamb, Elia, Ser. I. xvi. With the feeling of an English freeholder, that all betwixt sky and centre was my own.
b. The earth itself, as the supposed center of the universe.
1606. Shaks., Tr. & Cr., I. iii. 85. The Heauens themselues, the Planets, and this Center, Obserue degree, priority, and place.
1667. Milton, P. L., I. 74. As far remov’d from God and light of Heav’n As from the Center thrice to th’ utmost Pole.
† 3. The prick or dot in the middle of a circle; the hole pricked by the stationary point of a pair of compasses. [cf. Gr. κέντρον.] Obs.
c. 1391. Chaucer, Astrol., I. § 18. The centre þat standith a-Middes the narwest cercle is cleped the senyth.
1551. Recorde, Pathw. Knowl., I. Def., When a pricke standeth in the middell of a circle (as no circle can be made by compasse without it) then is it called a centre. Ibid., Cast. Knowl. (1556), 10. Although the earthe in it selfe haue a greate and notable quantity, yet in comparison to the firmament, it is to bee esteemed but as a centre or little pricke.
† b. Astrol. The sharp point or extremity of the metal tongue representing a star in the ‘rete’ of an astrolabe. Obs.
c. 1386. Chaucer, Frankl. T., 549. Ne hise rootes ne hise othere geeris As been his centris and hise Argumentz. Ibid. (c. 1391), Astrol., I. § 21. Of whiche sterres the smale poynt is cleped the Centre. Ibid., II. § 19. Set the Sentre of the sterre vp-on the est Orisonte.
4. The point, pivot, axis, or line round which a body turns or revolves; the fixed or unmoving center of rotation or revolution.
c. 1386. Chaucer, Squieres T., 14. Of his corage as any Centre stable.
1671. Milton, P. R., IV. 534. As a rock Of adamant, and as a centre, firm.
1677. Moxon, Mech. Exerc. (1703), 177. The Pole may move upon that Nail, or Pin, as on a Center.
1717. S. Clarke, Leibnitz’s 3rd Paper, § 17. If God would cause a Body to move free in the Æther round about a certain fixed Centre.
1825. J. Nicholson, Operat. Mechanic, 777. Gudgeon. The centres or pivots of a water-wheel.
1837. Carlyle, Fr. Rev. (1872), III. V. v. 197. Not even an Anarchy but must have a centre to revolve round.
5. A particular form of bearing adjustable in the direction of its length and having a conical point entering into a corresponding depression in the end of the revolving object which it supports. In the lathe, long works are supported either at one or both ends upon ‘centers.’
[1680. Moxon, Mech. Exerc., No. x. 180. Upon the points of this Screw [i.e., the ‘centre’] and Pike the centers of the Work are pitcht.]
1797. Trans. Soc. Arts, XV. 273. The treadle moveable at the end of the platform … between two centers.
1879. Holtzapffel, Turning, IV. 47. The crank [shaft] has been made to run in bearings, on centers. Ibid., IV. 91. The distance at which the axis of the lathe mandrel stands above the surface of the bed or bearers … called the height of center is used as the term to designate the dimensions of all lathes. Ibid., IV. 99. The five-inch centre lathe.
6. fig. a. The point round which things group themselves or revolve, or that forms a nucleus or point of concentration for its surroundings.
1685. Prideaux, Lett. (1875), 146. We live here remote from ye center of affairs.
1712. Steele, Spect., No. 474, ¶ 1. The Center of Business and Pleasure.
1796. H. Hunter, trans. St.-Pierre’s Stud. Nat. (1799), II. 492. The centre of all the powers of the kingdom.
1877. Mrs. Oliphant, Makers Flor., i. 1. The great centres of old Italian life, Rome and Venice and Florence.
1883. Gilmour, Mongols, xxxii. 366. The officers at the nearest military centres.
b. A point towards which things tend, move, or are attracted.
[1606. Shaks., Tr. & Cr., IV. ii. 110. The strong base and building of my loue Is as the very Center of the earth, Drawing all things to it.]
1626. Donne, Serm., iv. 31. A center of Reverence … to which all reverence flowed.
1653. Walton, Angler, ii. 63. Viewing the Silver streams glide silently towards their center, the tempestuous Sea.
1827. Pollok, Course T., V. Centre to which all being gravitates.
1850. Tennyson, In Mem., lxiv. The centre of a world’s desire.
c. A point from which things, influences, etc., emanate, proceed or originate. Esp. in biology, etc. (see also 7).
1738. Glover, Leonidas, VI. 250. The center of corruption.
1818. Sir H. Davy, Chem. Philos., 195. The light … proceeds in right lines or rays from the luminous body as a center.
1859. Darwin, Orig. Spec., xii. (1885), 322. The question of single or multiple centres of creation.
1865. Tylor, Early Hist. Man., i. 10. Diffused from a single geographical centre.
1872. W. Aitken, Sci. & Pr. Med. (ed. 6), II. 60. All new cells proceed from ‘centres of nutrition,’ from other cells, or from the nuclei of them.
1876. Mozley, Univ. Serm., ix. 188. Sick lives are centres of improving and refining influence.
7. a. Short for nerve-center.
1847. Carpenter, Zool., § 998. A number of ganglia or distinct centres of nervous action. From these diverging filaments are sent off, which are distributed to the various organs.
1869. Huxley, Phys., xi. 297. The grey matter of the upper part of the cord is … a vaso-motor centre for the head and face.
1881. Syd. Soc. Lex., s.v. Centre, visual, Destruction of this centre on one side causes complete, but temporary, blindness of the opposite eye.
b. Short for center of ossification (see 16).
1876. Quain, Anat. (ed. 3), I. 19. The lateral centres [for each vertebra] appear about the 7th week.
8. The name given to a leader of the Fenian organization, the chief being called head-centre.
1865. Ann. Reg., 178. In the language of the party he was termed the ‘Head Centre’ of the Fenians in Ireland.
9. The part of a target between the ‘bull’s-eye’ and the ‘outer.’ b. ellipt. The hitting of this.
1887. Whitaker’s Almanack, 540/1. [In this case] a bull’s-eye counts four points, a centre three, and an outer two.
II. Of other things, the middle point.
10. Geom. The point at equal distances from the extremities of a line, of any regular surface or solid, or at a mean distance from all points in the periphery of an irregular surface or body (center of magnitude); the central or middle point.
So the center of a regular polygon, quadrilateral figure, triangle, cube, cylinder, etc. Center of a conic section: the point which bisects any diameter, or in which all diameters intersect each other; the center of an ellipse or hyperbola, is the point midway between the two foci; that of a parabola is at infinity; center of a higher curve, the point in which two diameters meet; center of a dial, the part in which the gnomon intersects the plane of the dial.
1796. Hutton, Math. Dict., I. 262. Centre or center, a point equally remote from the extremes of a line, plane, or solid; or a middle point dividing them so that some certain effects are equal on all sides of it.
1840. Lardner, Geom., 91. Lines drawn from the centre to the angles of the polygon.
11. gen. The middle point or part, the middle or midst of anything.
1591. Shaks., 1 Hen. VI., II. ii. 6. The Market-Place, The middle Centure of this cursed Towne.
c. 1645. Howell, Lett., VI. 86. Though they dwelt in the center of Spain not far from Toledo.
1706. Addison, Rosamond, I. vi. Full in the center of the grove.
1776. Withering, Bot. Arrangem. (1796), I. 205. Florets all fertile, those of the center smaller.
1781. Cowper, Verses A. Selkirk, 3. From the centre all round to the sea.
1816. Scott, Antiq., vii. Near the centre of a deep but narrow bay.
1878. Morley, Carlyle, 175. The puniness of man in the centre of a cruel and frowning universe.
1880. E. Ingersoll, in Scribner’s Mag., June, 221/2. The centers of the great, gummy logs are eaten by the blaze.
b. fig. (or of things not material).
1628. T. Spencer, Logick, 169. Predication is the very Center, and life of Logicke.
1683. Tryon, Way to Health, 317. If the Disorder happen near the Center of Life.
1835. Browning, Paracelsus, Wks. I. 71. There is an inmost centre in us all, Where truth abides in fulness.
1846. Prescott, Ferd. & Is., I. Introd. 27. Those dismal scenes of faction which convulsed the little commonwealths to their centre.
c. Center of a bastion: ‘a point in the middle of the gorge of the bastion, from whence the capital line commences, and which is generally at the inner polygon of the figure’ (C. James).
12. The point or position of equilibrium of a body. Also fig. See also Center of gravity, of inertia in 16.
c. 1391. Chaucer, Astrol., I. § 2. Hit [the ring] disturbeth nat the instrument to hangen aftur his rihte centre.
1668. Temple, in Four C. Eng. Lett., 127. Things drawn out of their center are not to be moved without much force, or skill, or time; but, to make their return to their center again, there is required but little of either, for nature itself does all the work.
1704. Swift, Batt. Bks. (1711), 230. By his own unhappy Weight and Tendency towards his Center.
1860. Emerson, Cond. Life, Wks. (Bohn), II. 384. If the man is off his centre, the eyes show it.
13. Archit. A temporary framework supporting any superstructure; now spec. the wooden support and ‘mold’ upon which an arch or dome is supported while building.
1611. Shaks., Wint. T., II. i. 102. In those Foundations which I build vpon, The Centre is not bigge enough to beare A Schoole-Boyes Top.
1630. Prynne, Anti-Armin., 113. This … is the onely center vpon which the whole fabricke is erected.
1823. P. Nicholson, Pract. Build., 338. Centres.—The frame of timber-work for supporting arches during their erection.
1861. Smiles, Engineers, II. 182. The centres spanning the … width of the arch were composed of eight ribs.
14. Mil. a. The main body of troops occupying the space between the two wings. b. ‘The division of a fleet between the van and the rear of the line of battle, and between the weather and lee divisions in the order of sailing’ (Adm. Smyth).
1598. Barret, Theor. Warres, Gloss. 250. Centre, a French word, is the middle of a battell, or other things.
1710. Steele, Tatler, No. 210, ¶ 8. One [body] to be commanded by himself in the Center.
1769. Robertson, Chas. V., III. XII. 386. Brought some pieces of cannon to bear upon their center.
1871. Smiles, Charac., i. (1876), 17. At the combat of Vera, when the Spanish centre was broken.
c. The middle man of any rank of soldiers, or an imaginary point in the middle of any body of soldiers. ‘Centre of a battalion on parade: the middle, where an interval is left for the colors; of an encampment, it is the main street; and on a march, is an interval for the baggage; when it is so placed’ (C. James).
1672. Venn, Mil. & Mar. Discipline, I. 127. Secondly, Wheelings on the midst (or Center.) I shall not use the word Center, for it is more proper to a Circular body than to a square.
1796. Instr. Cavalry (1813), 226. The squadron will receive the word Center Dress.
1832. Prop. Reg. Instr. Cavalry, II. 33. Their Centres and Lefts move up.
15. Politics. In the French Chamber (which is arranged in the form of an amphitheater), the deputies of moderate opinions who occupy the central benches in front of the president, between the extreme parties who sit to the right and left. Right center, left center: divisions of this party inclining towards the opinions of the right and left, respectively, and sitting adjacent to them. Also transferred to the political opinions so indicated; and to the politics of other countries. In Germany the Center is the Catholic or Ultramontane party.
(This use originated in the French National Assembly of 1789, in which the nobles as a body took the position of honor on the President’s right, and the Third Estate sat on his left. The significance of these positions, which was at first merely ceremonial, soon became political.)
1837. Carlyle, Fr. Rev., VI. ii. Answered, from Right side, from Centre and Left, by inextinguishable laughter.
1874. Times, Summ. of Year, 31 Dec., 8/6. The Left Centre has withdrawn in some degree from its alliance with the Left, and overtures are from day to day on both sides tendered and rejected by the two divisions which form the Centre. Ibid. The party which is known in [the German] Parliament as the Catholic Centre.
1884. Bertha M. Gardiner, Fr. Rev., iii. 52.
III. 16. Phrases.
Center of attack (Mil.): ‘when a considerable front is taken before a besieged place, and the lines of attack are carried upon three capitals, the capital in the middle, which usually leads to the half-moon, is styled the center of attack’ (C. James).
Center of attraction (Physics): the point to which bodies tend by gravity, or by the action of centripetal force; (fig.) the object or point that attracts attention, interest or curiosity.
Center of buoyancy, of cavity, of displacement, of immersion: the mean center of that part of a ship or floating body, which is immersed in the water.
Center of conversion: the point in a body about which it turns or tends to turn when force is applied at a given point.
Center of curvature: see CURVATURE.
Center of friction: that point in the base of a body on which it revolves when put in rapid rotation, e.g., the point of the peg of a top.
Center of gravity orig. = center of attraction; afterwards, and still popularly (see quot. 1879) = center of mass: in the case of a single body or a system of bodies rigidly connected, the point about which all the parts exactly balance each other, and which being supported, the body or system will remain at rest in any position.
Center of gyration: the point at which if the whole mass of a revolving body were collected, the rotatory motion would remain the same.
Center of inertia: = center of gravity or mass.
Center of magnitude: = sense 10.
Center of mass: that point in relation to a body or system of bodies so situated that any plane whatever that passes through it divides the body or system into two parts of which the masses or weights are exactly equal.
Center of motion: the point that remains at rest while all the other parts move round it.
Center of oscillation: the point of a body suspended by an axis at which, if all the matter were concentrated, the oscillations would be performed in the time actually taken.
Center of ossification: the point (or points) in the cartilage or fibrous membrane of an immature bone in which the bone salts are first deposited, and from which they extend until the whole bone is ossified.
Center of percussion: in a moving body, that point where the percussion or stroke is greatest, in which the whole percutient force of the body is supposed to be collected.
Center of pressure: the point at which the whole amount of pressure may be applied with the same effect as when distributed.
1727–51. Chambers, Cycl., Center of Gravitation or *Attraction.
1796. Hutton, Math. Dict., Centre of *Conversion, a term first used by M. Parent.
1659. Leak, Water-works, 4. They fall towards their centre of *gravity in the Water.
1704. J. Harris, Lex. Techn., s.v. Earth, The Earth doth not describe an Orbit round the Sun properly by her own Centre, but by the Common Centre of Gravity of the Earth and the Moon.
1822. Imison, Sc. & Art, I. 449. The centre of gravity is that point in which the weight of a body may be supposed to be collected.
1831. Carlyle, Sart. Res. (1858), 150. The casting of this pebble from my hand alters the centre-of-gravity of the Universe.
1796. Hutton, Math. Dict., I. 269. The distance of the centre of *gyration, from the point of suspension, is a mean proportional between those of gravity and oscillation.
1829. Nat. Philos., I. Hydraulics, iii. 28 (Usef. Knowl. Soc.). The point of percussion, or of greatest effect, (which, in revolving bodies, is called the centre of gyration).
1879. Thomson & Tait, Nat. Phil., I. I. § 230. The Centre of *Inertia or Mass is thus a perfectly definite point in every body, or group of bodies. The term Centre of Gravity is often very inconveniently used for it.
1796. Hutton, Math. Dict., I. 267. Centre of *magnitude is … the same as the centre of gravity in homogeneal bodies, as in a cylinder or any other prism.
1727–51. Chambers, Cycl., s.v., If the weights P and Q revolve about the point N, so that when P descends, Q ascends, N is said to be the Center of *Motion. Ibid. He found, in this case, the distance of the centre of *oscillation, from the axis in a circle, to be 3/4 of the diameter.
1796. Hutton, Math. Dict., I. 267. Centre of oscillation … in a compound pendulum, its distance from the point of suspension is equal to the length of a simple pendulum whose oscillations are isochronal with those of the compound ones.
1867. J. Marshall, Outlines Physiol., II. 651. The cranial bones begin by one or more flat radiating centres of *ossification.
1869. Huxley, Physiol., xii. 321. A long bone has usually, at fewest, three centres of ossification.
1727–51. Chambers, Cycl., s.v., The center of *percussion is the same with the center of gravity, if all the parts of the percutient body be carried with a parallel motion.
1796. Hutton, Math. Dict., I. 269. When the percutient body revolves about a fixed point, the centre of percussion is the same with the centre of oscillation. Ibid. The centre of *pressure of a fluid against a plane, is that point against which a force being applied equal and contrary to the whole pressure, it will just sustain it.
IV. attrib. and in comb.
17. attrib. or quasi-adj. Of or pertaining to the center, central. Hence CENTREMOST.
1791. Bentham, Panopt., I. Postcr. 99. The center one of the 5 uppermost Cells.
1796. Instr. & Reg. Cavalry (1803), 306. Trumpeters and music are behind the center interval.
1829. I. Taylor, Enthus., ix. 219. The centre illusion of the system.
1860. J. Kennedy, Horse Shoe R., lvii. 586. The centre division of the assailing army.
1879. R. K. Douglas, Confucianism, iv. 92. The centre figures of his philosophy.
18. Obvious combinations: as centre-arbor, -line, -pin, -pinion, -point, -table, -truth, etc. Also centreward, centrewise advs.
1884. F. J. Britten, Watch & Clockm., 266. The *centre arbor … turns once in an hour.
1804. Med. Jrnl., XII. 202. The distance between the *centre-pin and blade.
1807–26. S. Cooper, First Lines Surg., 303. In order to fix the centre-pin of the trephine.
1884. F. J. Britten, Watch & Clockm., 266. The teeth round the barrel drive the *centre-pinion.
1648. Bp. Hall, Sel. Th., § 22. What a mere *centrepoint the earth is in comparison of the vast circumference of heaven.
1866. Liddon, Bampton Lect., V. (1875), 253. He [Christ] is the Centre-point of the history and of the hopes of man.
1868. ‘Holme Lee,’ B. Godfrey, II. xxxvi. 161. He … remained standing by the *centre-table.
1858. Sears, Athan., II. xi. 245. The *centre-truth in his system of doctrines.
1843. Carlyle, Past & Pr., I. ii. At all moments it is moving *centreward.
1853. Kane, Grinnell Exp., xvii. (1854), 126. It contracts itself *centrewise, and rounds itself endwise.
19. Special combs.: centre-chisel, a pointed cold-chisel; centre-chuck, a kind of chuck for a lathe; centre-drill, ‘a small drill used for making a short hole in the ends of a shaft about to be turned, for the entrance of the lathe-centres’ (Weale); centre-fire = central fire (see CENTRAL 4); also attrib., as in centre-fire cartridge; † centre-fish, a mollusk allied to the limpet; centre-lathe, a turning-lathe in which the work is supported or held by centers (sense 5); centre-piece, a piece in the center of anything; spec. an ornamental piece of plate or glass for the center of a table, etc., an épergne; centre-punch, a punch with a conical point for marking the center of work to be turned in the lathe, or the center of a hole to be drilled; centre-rail, a third or middle rail, sometimes used on railway lines, in connection with a cogged wheel or other device on the engine, for the ascent or descent of steep inclines; also attrib.; centre-saw, a kind of circular saw that cuts round timber in sections meeting in the center, for spokes, pick-handles, etc.; centre-second(s, applied to a seconds hand on a clock or watch mounted on the center arbor, and completing its revolution in one minute; also to a clock, etc., having such a seconds hand; centre-split (see quot.); centre-valve, in gas-works, a rotating valve by which the gas is distributed to several sets of purifiers; centre-velic, see VELIC; centre-wheel, the third wheel of a watch in some kinds of movements.
1863. Smiles, Indust. Biog., 247. His self-adjusting double driving *centre-chuck, for which the Society of Arts awarded him their silver medal in 1828.
1668. Wilkins, Real Char., II. v. § 2. 130. Univalvs; having but one shell; whether being Unmoved;… 1. Limpet. *Center fish.
1819. Rees, Cycl., s.v. Turning, Lathes are … called *centre lathes where the work is supported at both ends.
1879. Holtzapffel, Turning, IV. 99.
1836. Disraeli, H. Temple, VI. vi. (Hoppe). A bouquet which might have served for the *centre-piece of a dinner table.
1854. Illust. Lond. News, 18 March, 259/1. The … testimonial is a silver centre-piece consisting of a column encircled by two gracefully-formed figures representing Peace [etc.].
1858. Hawthorne, Fr. & It. Jrnls., II. 100. Constructed, with screws to tighten it, and a silver centre-piece between the two tongues.
1879. Holtzapffel, Turning, IV. 192. A steel *center punch is driven into the flat end.
1874. Knight, Dict. Mech., s.v., Another form of *center-rail railway. Ibid., s.v., The largest *centre-second clock … is the turret-clock for the Bombay Harbour Board [with] a dial 81/2 feet in diameter.
1884. F. J. Britten, Watch & Clockm., 49. [A] Centre Seconds … [is] a long seconds hand moving from the centre of a watch dial.
1886. Daily News, 15 Oct., 5/6. They are made of *‘centre splits.’ Good, honest hides, it appears, are skilfully split into three skins, and the centre one, having no grain, and being of a soft, flimsy substance, is nevertheless capable of being made to assume the guise of serviceable leather.
1884. F. J. Britten, Watch & Clockm., 266. The *centre wheel drives the third wheel pinion.
