Tri-

prefix, a. L. tri- and Gr. τρι-, combining form of trēs, τρεῖς three, τρίς thrice.

  The i, etymologically short in Greek and Latin, was in Latin sometimes lengthened, esp. in numerals (trīcēnī, trīgintā, etc.). In Eng. it is now usually long and diphthongal (əi), except in derivatives before two consonants, as triple, triptych, also in trilogy, trimeter. In scientific books tri- is often represented by the numeral, as 3-bracteate, 3-carbon.

  I.  Forming adjs. (and derived sbs. and advbs.) with the senses:

  1.  Having, characterized by, or consisting of (rarely, belonging or relating to) three (of the things denoted by the second element).

  a.  In comb. with adjs. derived from sbs. (usually L. or Gr.), or less commonly with the sb. without adjectival termination. Trincnodal Geom., having three acnodes or conjugate points (see CONJUGATE a. 6 a). Triact, Triactinal, Triactine Zool. [Gr. ἀκτίς, ἀκτῑν- ray], having three rays: said of a sponge-spicule. Trialate Nat. Hist. [L. āla wing], three-winged (Cent. Dict., 1891). Triannalate Zool. [L. annulus ring], having or consisting of three rings. Trianthous Bot. [Gr. ἄνθος flower], having three flowers. Triarctic (see quot.). Triarcuated [L. arcu-s bow, ARCH], three-arched. Triareal, comprising or divided into three areas. Triaxon, -onian, -onid [Gr. ἄξων axis], of sponge-spicules: having three axes; = TRIAXIAL. Tribasilar Anat., designating a bone formed by union of three bones at the base of the skull. Triblastic Zool. [Gr. βλαστός germ], having three layers (epiblast, mesoblast, hypoblast) in the blastoderm of the embryo. Tribracteate Bot., having three bracts; so Tribracteolate, having three bracteoles or minute bracts. Tricarinate, -ated Nat. Hist. [L. carīna keel], having three keels or ridges. Tricarpellary, Tricarpellate Bot., consisting of or having three carpels. Tricarpellite [ad. mod.L. Tricarpellītēs], a fossil tricarpellary nut-like fruit, found in the London Clay. Tricarpous Bot. [Gr. καρπός fruit], ‘bearing three fruits or three carpels’ (Syd. Soc. Lex., 1899). Tricaudal, Tricaudate [L. cauda tail], having three tails or tail-like processes, as the retrahens auris or tricaudālis muscle, or the hind margin of the posterior wings in some Lepidoptera. Tricellular, having or consisting of three cells. Tricentral, having three centers; so † Tricentreity, the fact or attribute of having three centers. Tricephalic, Tricephalous [Gr. τρικέφαλος, f. καφαλή head], having three heads, three-headed. Tricolumnar, having three columns; arranged in or occupying three columns of print. Tricornigerous [late L. tricorniger, f. cornu horn: see -GEROUS], Tricornute, Tricornuted, three-horned; having three horn-like processes. Tricoryphean [Gr. κορυφή peak], having three peaks. Tricostate [COSTATE], three-ribbed. Tricotyledonous Bot., having three cotyledons. Tricrunodal Geom., having three crunodes. Tricrural [L. crūs, crūr- leg), three-legged; consisting of three branches radiating from a common center. Tridiametral, having three diameters. Tridigitate, (a) Zool. having three digits (fingers or toes); (b) Bot. digitate with three leaflets, ternate; so Tridigital, Tridigitated. Tridynamous Bot. [after DIDYNAMOUS, TETRADYNAMOUS], having six stamens of which three are longer than the others. Tri-elementary, composed of three elements. Trifasciated Zool. [L. fascia band], having or marked with three bands. Trifaucian [L. trifaux (Vergil Æn. vi. 417), f. faucēs throat], having three throats. Trifilar [L. fīlum thread], consisting of three threads. † Trifistulary [L. fistula pipe], having three pipes or tubes. Triflagellate Biol., having three flagella, as an infusorian. Trifloral, Triflorous Bot. [L. flōs, flōr- flower], bearing three flowers (on one stem); three-flowered. Trifoveolate, -ated Entom., having three foveolæ or shallow pits. Trigastric Anat. [after DIGASTRIC], having three bellies, as a muscle. Trigeneric Gram. [GENERIC], of three genders. Triglandular Bot. [mod.L. glandula (GLANDULE), dim. of glans acorn], ‘having three nuts or nutlets in one involucre’ (Cent. Dict., 1891). Triguttulate Nat. Hist. [GUTTULATE], having three spots like small drops. Trihemeral [Gr. τριήμερος, f. ἡμέρα day], lasting three days. Trihilate Bot. [HILUM]: see quot. Trihypostatic, existing in three ‘hypostases’ or ‘persons’: see HYPOSTASIS 5 (b). Trijugate, Trijugous Bot. [L. jugum yoke; cf. trijugus triple], having three pairs of leaflets: said of a pinnate leaf. Trilabiate Nat. Hist. [L. labi-um lip], three-lipped. Trilamellar, Trilamellated, Trilamellated, Trilaminar, Trilaminate Nat. Hist. [LAMELLA, LAMINA], having or consisting of three layers. Trilophodont a. Zool. [Gr. λόφος ridge + ὀδούς, ὀδοντ- tooth], having molar teeth with three transverse ridges, as the genus Trilophodon of mastodons. Trilophous [Gr. λόφος crest], having three rays forked, as a sponge-spicule. Triluminar, Triluminous [L. lūmen light], ‘haying three lights’ (Bailey, 1727). Trimastigate Biol. [Gr. μάστιξ, -ῑγ- whip] = triflagellate. Trimembral, ‘having, or consisting of, three members’ (Webster, 1864). Trimuscular, furnished with three muscles. Trinoctial [L. nox, noct- night], belonging to or lasting three nights. Trinucleate Biol., having three nuclei. Triocular [L. oculus eye], having three eyes. Trioperculate Nat. Hist., having three opercula (see OPERCULUM). Triorthogonal Geom. [ORTHOGONAL], pertaining to or consisting of three systems of lines or surfaces, each intersecting the other two at right angles. Triovulate Bot., having three ovules. Tripaleolate Bot.: see quot. Tripapillated Zool., having three papillæ. Tripaschal [PASCHAL], including three passovers. Triphasic, having or exhibiting three phases. Triphyletic [Gr. φυλετικ-ός, f. φυλέτης tribesman, φυλή tribe]: see quot. Tripolar, having or characterized by three poles. Triprosthomerous Comp. Anat. [f. prosthomere, f. Gr. πρόσθεν forwards + μέρος part], consisting of three prosthomeres, i.e., somites which, with their parapodia, have passed forwards from the thorax. Triprostyle [PROSTYLE], of an ancient temple: having a portico with three pillars in front (also said of the portico). Tripunctal [med.L. tripunctālis (Wyclif), L. punct-um point: cf. PUNCTAL)], occupying three points in space. Tripunctate [L. punct-um point], marked with three points or dots. Tripupillate Entom. [cf. PUPILLATE], having three ‘pupils’ or included spots, as an ocellated spot on an insect’s wing. Tripyramidal Cryst., characterized by three types of pyramid: applied to a class of the hexagonal system. Triquadrantal Geom., formed by three quadrants, as a spherical triangle. Trirectangular, having three right angles, as a spherical triangle (Worcester, 1860). Trirhombohedral Cryst., characterized by three types of rhombohedron: applied to a class of the hexagonal system. Trisceptral, having, or pertaining to, three scepters. Trisensory, pertaining to or affecting three of the senses. Trisepalous Bot., having or consisting of three sepals. Triseptate, having three septa or partitions. Triserial (whence Triserially adv.), Triseriate, arranged in three series or rows. Trisetose Entom., bearing three setæ or bristles (Cent. Dict., 1891). Trisinuate, Trisinuated, having three sinuses or inward curves, as the margin of an insect’s wing. Trispermous Bot. [Gr. σπέρμα seed], containing three seeds. Trispinose, Trispitnous Nat. Hist., having three spines. Trisplanchnic Anat. [Gr. σπλάγχνα viscera], applied to the sympathetic nerve, as having connections with the viscera of the three great cavities (cranial, thoracic, abdominal) of the body. Trisporic, Trisporous Bot., having or consisting of three spores. Tristachyous Bot. [Gr. στάχυς ear of corn, spike], having three spikes. Tristigmatic, Tristigmatose Bot., having three stigmas. Tristylous Bot., having three styles. Triverbal [L. verb-um word], consisting of three words. Triverbial [f. L. tria verba three words]: see quot. Trivertebral Anat., consisting of three vertebræ united. Trivirgate Zool. [L. virga twig, rod, stripe], marked with three streaks or stripes. Trivoluminous, consisting of three volumes; composing a work in three volumes. Trizomal Geom. [Gr. ζῶμα girdle], applied to a curve having an equation of the form √U + √V + √W = 0: cf. POLYZOME, and tetrazomal s.v. TETRA-.

  b.  With Eng. sbs. (without adj. ending); chiefly nonce-wds. instead of the usual formations in three-: as tri-church, -letter, -party, -phase.

  c.  Occas. with sb. + -ED² (instead of the usual three- … ed): as tri-bladed, -breakered, -cornered, -faced, -legged, -membered, -pointed, -sceptred, -shaped, -zoned.

1873.  Salmon, Higher Plane Curves, 245. The quartic is a *triacnodal curve composed of a trigonoid figure within the triangle and of the three vertices as acnodes.

1886.  Lendenfeld, in Proc. Zool. Soc., 560. The calcareous triaxon spicules have only three rays—*triact.

[1886.  Proc. Zool. Soc., 21 Dec., 563. Triactina, with three rays.]

1891.  Cent. Dict., *Triactinal.

1887.  Sollas, in Encycl. Brit., XXII. 416. (Fig. 12) c, triod (triaxon *triactine).

1901.  Proc. Zool. Soc., 5 March, 197. The sixth [segment] is *triannulate.

1891.  Cent. Dict., *Trianthous.

1883.  A. R. Wallace, in Nature, 22 March, 482/2. Heilprin … seeks to show that the Neoarctic and Palæarctic should form one region, for which he proposes…. *‘Triarctic Region,’ or the region of the three northern continents.

1822.  J. Parkinson, Outl. Oryctol., 264. A series of *triarcuated, imbricating, transverse slips.

1897.  Allbutt’s Syst. Med., II. 142. Gresswell, under the names *‘triareal’ and ‘pentareal,’ has described certain peculiarities of the tongue.

1886.  *Triaxon [see triact].

1887.  Amer. Nat., Oct., 938. A *triaxonian star with five or six rays.

1911.  Encycl. Brit., XXV. 729/1. Sponges with a skeleton composed of siliceous spicules,… either *triaxonid and hexactinellid in form, or derivable from the triaxonid … type.

1878.  Bartley, trans. Topinard’s Anthrop., v. 173. Cretinism, according to [Virchow] is due to the synostosis of the *tri-basilar bone—that is to say, of the spheno-basilar suture, and the suture of the body of the anterior sphenoid and the posterior sphenoid.

1890.  H. M. Stanley, Darkest Africa, II. xxi. 22. *Tri-bladed and four-bladed knives were shown to me.

1901.  Science, 6 Dec., 891/2. A possible basis for a division of the *‘triblastic’ animals into two parallel but independent series.

1870.  Hooker, Stud. Flora, 305. Flowers … in 1- or more-flowered *3-bracteate spikelets. Ibid., 321. Flowers … minutely *3-bracteolate.

1834.  Medwin, Angler in Wales, I. 258. Along the *tri-breakered sea-shore.

1897.  Proc. Zool. Soc., 2 Feb., 198. Dorsal scales very strongly *tricarinate.

1802.  Shaw, Gen. Zool., III. 54. *Tricarinated Tortoise.

1872.  Oliver, Elem. Bot., II. 253. A *tricarpellary pistil.

1900.  B. D. Jackson, Gloss. Bot. Terms, *Tricarpellate.

[1859.  Page, Handbk. Geol. Terms, *Tricarpellites..., fossil nut-like fruits from the London clay, so called from their consisting of three carpels or seed-cells.]

1882.  Ogilvie, Tricarpellite.

1891.  Cent. Dict., *Tricarpous.

1860.  Mayne, Expos. Lex., Tricaudalis, having three tails; three-tailed: *tricaudal.

1891.  Cent. Dict., *Tricaudate. Ibid., *Tricellular.

1900.  in B. D. Jackson, Gloss. Bot. Terms.

1642.  H. More, Song of Soul, II. iii. II. vi. The second way that makes the soul *tricentrall. Ibid., I. viii. The *Tricentreity Of humane souls.

1913.  19th Cent., Aug., 284. The dual monarchy is not only bicephalic … but … *tricephalic.

1891.  Cent. Dict., *Tricephalous.

1907.  Daily News, 13 March, 2. The *Tri-Church Conference of the Congregational, United Brethren, and Methodist Protestant Churches of the United States.

1852.  N. Y. Times, 8 May, 2/3. M. Girardin writes a *tri-columnar article against the Empire, and forebodes assassination as the fate of the Prince, should he exchange the simple toga for the imperial robe.

1865.  Pall Mall G., 15 June, 9. The tricolumnar ‘Historicus’ favours the Times at his usual length with a letter.

1892.  Athenæum, 4 June, 725/1. Fifty-six pages of index, mostly tricolumnar.

1819.  Keats, Lett. to G. & Georgiana Keats, 13 March. The black badger with *tri-cornered hat.

1903.  Bradford Antiq., July, 348. Tricornered bits of wood.

1727.  Bailey, vol. II., *Tricornigerous..., bearing or having three Horns.

1888.  R. W. Shufeldt, in Jrnl. Comp. Med. & Vet. Arch., X. 138. A tricornute hypapophysis is beginning to be developed.

1816.  G. S. Faber, Orig. Pagan Idol., II. 502. The Mount of Olives; which he adopted as the local *tricoryphèan Meru or Ida of his apostasy.

1861.  Bentley, Man. Bot. (1870), 146. If a ribbed leaf has 3 ribs … it is said to be 3-ribbed or *tricostate.

1828.  Brande, in Lancet, 14 June, 323/1. Containing three [cotyledons], *tricotyled[on]ous.

1873.  Salmon, Higher Plane Curves, 245. If the ellipse cuts each side in two real points, then the quartic is *tricrunodal.

1873.  Hooker, trans. Le Maout’s Bot., 915. The macrospores are marked on one hemisphere with a *tricrural line.

1891.  Cent. Dict., *Tridiametral,… *Tridigitate.

1881.  *Tridigital [see BIDIGITATE].

1900.  B. D. Jackson, Gloss. Bot. Terms, Tridigitate,… thrice digitate, ternate.

1811.  Shaw, Gen. Zool., VII. 105. *Tridigitated Kingfisher … is a native of New Holland;… the legs and feet red, with three toes only.

1866.  Odling, Anim. Chem., 25. Comparing *tri-elementary bodies of this kind with tri-elementary mineral substances.

1835.  Burnes, Trav. Bokhara (ed. 2), II. 162. The great *trifaced idol of Elephanta.

1777.  Pennant, Zool. (ed. 4), IV. 75. Tellina … *Trifasciated, with a very brittle shell.

1802.  Shaw, Gen. Zool., III. 542. Trifasciated Snake.

1716.  M. Davies, Athen. Brit., II. To Rdr. 41. Those reviving Hydra’s and Triceptick or *Trifaucian Cerberus’s have been often and are still daily baffl’d and defeated.

1903.  Nature, 5 Feb., 334/1. An inertia table … in which an aluminium ring was supported by a *trifilar suspension.

1646.  Sir T. Browne, Pseud. Ep., III. xii. 132. Nor will the solitude of the Phænix allow this denomination, for many there are of that species, and whose *trifistulary bill and crany we have beheld our selves.

1891.  Cent. Dict., *Triflagellate … *Trifoveolate.

1860.  Worcester, *Trifloral.

1771.  J. R. Forster, Flora Amer. Septentr., 25. Ranunculus abortivus … *triflorous.

1861.  Hagen, Synopsis Neuroptera N. Amer., 193. Each side with a fuscous, *trifoveolated stripe.

1676.  Phil. Trans., XI. 770. He makes an ingenious supposition of a *trigastrick muscle.

1880.  Earle, Philol. Eng. Tongue, § 420. The old adjective had … even a double set of *trigeneric inflections.

1887.  W. Phillips, Brit. Discomycetes, 27. Sporidia 8, narrowly fusiform, bi- or *tri-guttulate.

1840.  G. S. Faber, Prim. Doctr. Regen., II. vi. 140. You were thrice plunged into the Water,… symbolically exhibiting the *trihemeral continuance of Christ in the sepulchre.

1866.  Treas. Bot., *Trihilate, having three apertures, as some sorts of pollen grains.

1862.  Neale, Hymns East. Ch., 32. Three co-eternal, co-enthroned,… *Trihypostatic Essence.

1880.  Gray, Struct. Bot. (ed. 6), 417/2. Pinnate leaves are unijugate, with a single pair of leaflets, bijugate, with two pairs, *trijugate, with three pairs [etc.].

1819.  Pantologia, *Trijugous leaf,… a pinnate leaf with three pairs of leaflets.

1856–8.  W. Clark, Van der Hoeven’s Zool., I. 192. Body anteriorly obtuse,… Mouth *trilabiate.

1900.  B. D. Jackson, Gloss. Bot. Terms, *Trilamellar.

1822.  J. Parkinson, Outl. Oryctol., 186. One [tooth of the shell] … slightly *trilamellated.

1882.  Sladen, in Jrnl. Linn. Soc., XVI. 243. The spinelets are … regularly *trilaminate.

1844.  Tupper, Crock of G., ii. A ricketty triangular and *trilegged table.

1902.  Westm. Gaz., 6 Aug., 6/1. A new telegraphic code has been invented … known as Baldrey’s *Tri-Letter Code…. Every word in any language is represented by three letters only.

1909.  Cent. Dict., Supp., *Trilophous.

1891.  Cent. Dict., *Trimastigate.

1626.  Prynne, Perpet. Regen. Man’s Est., 331. A threefold and *trimembred objection.

1875.  C. C. Blake, Zool., 108. The larynx is *trimuscular.

1623.  Cockeram, *Trinoctial, belonging to three nights.

1880.  Muirhead, Gaius, Digest 623. Manus,… avoidance of it by trinoctial interruption.

1887.  W. Phillips, Brit. Discomycetes, 254. Sporidia … *3-nucleate or pseudo-septate.

1844.  Tupper, Heart, iv. Men … being neither naturally monocular nor *triocular.

1900.  B. D. Jackson, Gloss. Bot. Terms, *Trioperculate.

1891.  Cent. Dict., *Triovulate.

1866.  Treas. Bot., 1172. *Tripaleolate, consisting of three pales or paleæ, as the flower of a bamboo.

1891.  Cent. Dict. cites H. Allen for *Tripapillated.

1907.  Daily Chron., 11 March, 4/4. The great danger ahead of Australia is … her *tri-party system of government, which places parties in office that do not command the confidence of the country.

1883.  Schaff, Hist. Chr. Church (ed. 2), I. § 16. 130. Three theories [of the length of Christ’s public ministry],… designated as the bipaschal, *tripaschal, and quadripaschal schemes, according to the number of Passovers.

1900.  Engineering Mag., XIX. 778/2. The Central Station of the *‘Tri-Phase’ Company at Asnières, Seine … which will furnish tri-phase currents to Paris.

1901.  Buck’s Handbk. Med. Sc., III. 105. In the frog’s heart the variation shown by the capillary electrometer is diphasic. For the human heart the later work seems to show a *triphasic current.

1900.  B. D. Jackson, Gloss. Bot. Terms, *Triphyletic,… used of hybrids containing the blended strains of three species.

1605.  Sylvester, Du Bartas, II. iii. III. Lawe, 487. ’Gainst the *tri-pointed wrathfull violence of the drad dart.

1865.  Mansfield, Salts, 33. The general idea of a *tripolar compound, the simplest form of which is supposed to be water.

1894.  Bateson, Variation, xvi. 430. Tripolar division of nucleus in embryonic tissue of Trout.

1902.  E. R. Lankester, in Encycl. Brit., XXV. 700. Arthropoda—Hexapoda. Head shown by its early development to be *triprosthomerous.

1841.  Civil Engin. & Arch. Jrnl., IV. 118/2. Only the portico part of the temple (a Corinthian hexastyle, *triprostyle) advanced into the enclosed area in front.

1841.  Penny Cycl., XX. 74/2, Roman Architecture.

1897.  Dziewicki, Wyclif’s De Logica, III. Introd. 23. If the Equator consist of *tripunctal atoms, it cannot be a circle.

1872.  Nicholson, Palæont., 491. Oval or elliptical *tripunctate areoles.

1826.  Kirby & Sp., Entomol., IV. xlvi. 287. An ocellus is called bipupillate, *tripupillate, etc., when there are two, three, etc. of these spots.

1896.  C. W. Crockett, Elem. Plane & Sph. Trigon., 126. A *triquadrantal triangle has three sides each equal to a quadrant. Ibid. A *trirectangular triangle is also triquadrantal.

a. 1886.  Ferguson, Ogham Inscript. (1887), 153. This symbol in a bi-sceptral form traverses the crescent; in a *tri-sceptral form, the other emblem.

1792.  J. Barlow, Conspir. Kings, 78. The *trisceptred prince, of Austrian mould… Theresa’s son.

1895.  Edin. Rev., Jan., 108. A *‘trisensory hallucination,’ ‘visual,’ ‘auditory,’ and ‘tactile.’

1903.  F. W. H. Myers, Human Personality, I. 254. The statistical proportions of visual, auditory, bisensory, and trisensory hallucinations have not been worked out.

1830.  Lindley, Nat. Syst. Bot., 286. *Trisepalous calyx.

1874.  Cooke, Fungi, 27. The spores … at first unilocular, but afterwards *triseptate.

1860.  Worcester, *Triserial, *Triseriate (Bot.), in three rows, one below another. Gray.

1866.  Treas. Bot., 1174. Triserial, in three rows.

1891.  Cent. Dict., *Triserially, in three series; so as to be triserial.

1613.  Heywood, Silver Age, III. Wks. 1874, III. 156. The triple-headed dogge … Hels *tri-shap’t porter.

1891.  Cent. Dict., *Trisinuate.

1849.  Johnston, in Proc. Berw. Nat. Club, II. No. 7. 366. The frontal margin *trisinuated.

1760.  J. Lee, Introd. Bot., II. (1765), 159. Rhamnus, with a *trispermous Fruit.

1819.  G. Samouelle, Entomol. Compend., 93. Interior antennæ with the first joint of the peduncle *trispinose.

1828.  Stark, Elem. Nat. Hist., II. 162. Thorax granulated, carinated, *trispinous.

1826.  Kirby & Sp., Entomol., IV. xxxvii. 4. Called the great sympathetic, the intercostal, or *trisplanchnic nerves.

1857.  Dunglison, Med. Lex., Trisplanchnic Nerve.… Great sympathetic, Intercostal, Ganglionic or vertebral nerve.

1866.  Treas. Bot., 1174. *Trisporic.

1891.  Cent. Dict., *Trisporous. Ibid., *Tristachyous. Ibid., *Tristigmatic … *Tristigmatose.

1900.  B. D. Jackson, Gloss. Bot. Terms, Tristigmatic.

1891.  Cent. Dict., *Tristylous.

1900.  in B. D. Jackson, Gloss. Bot. Terms.

1817.  Jas. Mill, Brit. India, I. II. vi. 279. The *triverbal phrase, and the triliteral syllable.

1768.  Blackstone, Comm., III. xxvi. 424. In the Roman calendar there were in the whole year but twenty eight judicial or *triverbial days allowed to the praetor for hearing causes [note, Otherwise called dies fasti, in quibus licebat praetori fari tria verba, do, dico, addico].

1871.  Huxley, Anat. Vertebr. Anim., viii. 341. The last cervical and the anterior dorsal vertebræ [in Glyptodon] are ankylosed together into a single *‘tri-vertebral’ bone.

1863.  Ibis, Jan., 15. Acc[ipiter] nisoides … closely resembles the preceding one, A. nisus, but is smaller, with *trivirgate throat.

1857.  Reade, Course of True Love, 191. Paper is not absolutely valueless, whatever the *trivoluminous may think.

1892.  Athenæum, 31 Dec., 914/2. In tri-voluminous fiction.

1867.  Cayley, Math. Papers, VI. 485. On the *Trizomal Curve and the Tetrazomal Curve.

1840.  R. Horne, Gregory VII., V. iv. (ed. 2), 100. *Tri-zoned Jove’s star-set eternity.

  2.  Triply; three times; in three ways, directions, etc. Tricurvate, ‘curved in three directions, as a sponge-spicule’ (Funk’s Stand. Dict.). Triequal, constituting three that are equal. Trigoneutic a. [Gr. γονεύειν to generate], producing three broods in a year, as certain insects (cf. trivoltine in 4 b); so Trigoneutism. Trilarcenous, three times convicted of larceny. Triquadrifid Bot. [QUADRIFID], having three lobes each deeply divided into four segments. Triquinate Bot. [QUINATE], having three lobes each divided into five. Trisonant [L. sonānt-em sounding], sounding in three ways; in quot. loosely, comprising three classes of vocal sounds. Trisquare, ‘three-square; having three equally wide plane faces’ (Cent. Dict. Suppl., 1909). Tritactic Geom. [L. tact-, ppl. stem of tangĕre to touch: cf. TACTIC a.²], having or involving three coincident points of contact. Also TRITERNATE. b. spec. in Cryst. denoting forms having three ranges of facets, the number in each range being expressed by the second element: as tri-dodecahedral (12), tri-hexahedral (6), tri-octahodral (8); also tri-rhomboidal, having eighteen faces occupying the positions of those of three different rhomboids.

1805–27.  R. Jameson, Char. Min. (ed. 3), 205. *Tri-dodecahedral red silver-ore … a six-sided prism, acuminated on the extremities with three planes, and truncated on all the edges.

1839.  Bailey, Festus, v. (1848), 44. Injustice, hate, uncharitableness, *Triequal reign round earth, a Trinity of Hell.

1805–17.  R. Jameson, Char. Min., 204. *Trihexahedral,… when [the crystal’s] surface consists of three … ranges of planes, disposed six and six above each other…. Tri-hexahedral nitrate of potash…; a six-sided prism, acuminated on both extremities with six planes.

1823.  Syd. Smith, Botany Bay, Wks. (1850), 369. The man of three juries, who has three times appeared at the Bailey, *trilarcenous.

1805–17.  R. Jameson, Char. Min., 205. *Tri-octahedral sulphat of lead,… a four-sided pyramid,… the edges of the common base truncated, the angles on it very deeply bevelled, the bevelling planes set on the lateral edges, and the bevelling edges again deeply truncated, so that the crystal … consists of three rows of planes, of which each row contains eight planes.

1833.  Hooker, J. E. Smith’s Eng. Flora, V. I. 113. The upper leaves … are *tri-quadrifid.

1891.  Cent. Dict., *Triquinate.

1805–17.  R. Jameson, Char. Min., 202. *Trirhomboidal; this, in the Wernerian Crystallography, is a double six-sided pyramid, with alternately broad and narrow lateral planes,… and. acuminated on the extremities with three planes, which are set on the smaller lateral planes. Example, *Tri-rhomboidal calcareous-spar.

1876.  Douse, Grimm’s L., xlvii. 97. The priority of any one of the known *tri-sonant systems over the others is untenable.

  3.  In combination with an adj. (usu. in -ly) derived from a sb. denoting a period of time: Comprising three ——, lasting three ——, occurring or appearing every three (days, etc.); also (loosely) occurring three times (a day, etc.); those in -ly are also used as advbs. = every three (days, etc.) or three times a (day, etc.): as tridaily; trihoral [L. hora hour]. See also TRIMONTHLY, -WEEKLY; TRIANNUAL, -DIURNAL, etc.

1887.  Science, IX. 79. The system of *tridaily [meteorological] observations.

1855.  Ld. Ellesmere, in Jrnl. Geogr. Soc., XXV, p. xcvii. He [Dr. P. C. Sutherland] had kept up a series of *trihoral observations throughout the voyage.

  II.  4. Forming sbs., with the senses: a. Something consisting of or equivalent to three (of the things denoted by the second element); a triple ——. ǁ Triachænium (irreg. -akenium) Bot. [mod.L.: see ACHENE], a fruit composed of three achenes. Triaster Biol. [Gr. ἀστήρ star: cf. DIASTER], a figure bearing some resemblance to three conjoined stars, resulting from a tripolar division of a nucleus. † Tricube Math. Obs., the third power of a cube, a ninth power. † Tridiapason Mus. Obs. [DIAPASON 1], an interval of three octaves, a twenty-second. † Trifluctuation Obs. [L. fluctus wave]: see quot. Trihemiobol [Gr. τριημιωβόλιον], an ancient Greek coin of the value of 1¹/₂ obols. Trijunction, a junction or union of three. † Trimillion, the third power of a million; also (quot. 1707) a thousand thousand millions, i.e., a billion (= TRILLION in both senses: cf. etymology of BILLION). Trimillionaire [after millionaire], a person possessed of three millions of money (pounds, dollars, francs, etc.). Tripair Math., a set of three pairs. † Tripapalty [PAPALTY], a period during which there were three rival popes. † Triquadrate Math Obs. [QUADRATE sb.¹ 1 b], the third power of a square, a sixth power. Tristigm Geom. [Gr. στίγμα prick, point], a system of three points with the straight lines connecting them (Cent. Dict. Suppl., 1909).

  b.  Something having, or related in some way to, three (of the things denoted or indicated by the second element). Tricephal [Gr. τρικέφαλος adj., f. κεφαλή head: see tricephalic in I. 1 a], a three-headed figure or image of a deity. ǁ Triorchis [mod.L., f. Gr. ὄρχις testicle; cf. τριόρχης]: see quot. 1857. Triplane, an aeroplane with three supporting planes; also attrib. Triquaternion Math., an expression of the form q₁ + ωq₂ + μq₃, where q₁, q₂, q₃, are quaternions, and ω and μ are commutative with quaternions. Trisacramentarian, one who recognizes three and only three sacraments. Trivoltine [Ital. volta turn, time], a silkworm of a breed which yields three cocoons in a year.

  c.  Something (denoted by the second element) having three of some characteristic part, or related to three things. Tri-car (-machine, -mobile, -motor-car), a motor-car with three wheels; a motor tricycle with a seat for a person or a carrier for luggage in front. Triceptor Phys. Chem. [L. -ceptor = captor taker], an intermediary body having three haptophorous groups. Tricoaster, a combination of a three-speed gear with a ‘coaster’ brake on a cycle. † Triplurality, a plurality in which three benefices are held at once. Tripyramid Cryst., a triangular pyramid, as a form in certain calcareous spars. Tri-schism (nonce-wd.), schism of three parties. Tri-spear (nonce-wd.), a trident.

1882.  Ogilvie, *Triachenium, triakenium.

1900.  B. D. Jackson, Gloss. Bot. Terms, Triachænium.

1894.  Bateson, Variation, I. xvi. 431, note. A case of the presence of *triasters in two bilaterally symmetrical tracts of the blastoderm of Loligo.

1909.  J. W. Jenkinson, Experim. Embryology, 30. Triaster, a tripolar figure with three spindles.

1904.  Sat. Rev., 20 Feb., 228/1. The development of the *tri-car is especially important. Ibid. There is a great future for the useful tri-car.

1906.  Westm. Gaz., 21 Aug., 4/2. Experience is going to show that the final form of the tri-car for delivery purposes will be of a very different pattern.

1888.  Rhys, Hibbert Lect., i. 81, note. The wide distribution of the *tricephal has induced M. Mowat to declare for the improbable hypothesis, that it was … but the Roman Janus … naturalized in Gaul.

1902.  Vaughan & Novy, Cellular Toxins (ed. 4), 132. The intermediary body [usually an] ‘amboceptor,’… may be a *triceptor, quadriceptor, etc.

1908.  Daily Chron., 21 Nov., 9/4. He made use of the Sturmey-Archer *Tricoaster, which is the three-speed gear in association with a foot-acted brake.

1674.  Jeake, Arith. (1696), 273. Some to shorten … the long Names of … Higher Powers … call … φ φ a Bicube, φ φ φ a *Tricube &c.

1811.  Busby, Dict. Mus. (ed. 3), *Tri-Diapason.

1646.  Sir T. Browne, Pseud. Ep., VII. xvii. 377. Τρικυμία … is a concurrence of three waves in one, whence arose the proverb, τρικυμία κακῶν, or a *trifluctuation of evils.

1887.  B. V. Head, Hist. Numorum, 336. There are also *trihemiobols … of later style, for the Pegasus on the obverse has pointed wings.

1870.  Brooklyn Union, 10 Sept., 2/3. Mark Twain is the top-off-ographer of the Buffalo Express. He has just finished a lovely view of Paris, situated on the *trijunction of the Rhine, the Seine, and the Erie Canal.

1887.  Athenæum, 29 Jan., 164/2. To have the trijunction of Tibet, India, and Burma focussed within the four corners of a map.

1707.  Curios. in Husb. & Gard., 155. These ten Thousand Willows … will produce each of them likewise a hundred more. Thus we have a Million; then a hundred Millions: next come the Tens of Bimillions; then the *Trimillions.

1806.  [see TRILLION].

1848.  Tait’s Mag., XV. 646. A *tri-millionaire buys it for a deer-forest.

1905.  Westm. Gaz., 28 Dec., 7/3. Returning home in a *tri-motor-car.

1650.  H. More, Observ., in Enthus. Tri., etc. (1656), 92. If you have not a sleight of Art to Metamorphize your selves into *Triorchises.

1857.  Dunglison, Med. Lex., Triorchis, one who has three testicles.

1878.  Cayley, Math. Papers, X. 450. We have thus … a system of … 63 hexpairs; and selecting at pleasure any three pairs out of the same hexpair, we have a system of (63 × 20 = ) 1260 *tripairs.

1651.  N. Bacon, Disc. Govt. Eng., II. xvii. (1739), 89. During the *Tripapalty much money had been levied … to serve for the recovery of the Popedom to one of an English interest.

1908.  Times, 3 Oct., 6/3. Experiments with a *triplane machine.

1909.  Westm. Gaz., 4 March, 4/2. In machines of the biplane and triplane types.

1425.  Rolls of Parlt., IV. 290/2. That mony a Parsone … have pluralite, and somme *tripluralite.

[1753.  Chambers, Cycl. Supp., *Tripyramides,… the name of a genus of spars…. The bodies of this genus are spars, composed of single pyramids, each of three sides,… affixed by their bases to some solid body.]

1828.  Webster, Tripyramid.

1674.  Jeake, Arith. (1696), 273. Some … call ʓʓ a Biquadrate, ʓʓʓ a *Triquadrate.

1902.  G. Combediac, cited in Cent. Dict. Supp., for *Triquaternion.

1727–41.  Chambers, Cycl., *Trisacramentarians,… a sect … who admit of three sacraments, and no more…. There have been several trisacramentarians among the protestants, who allowed of baptism, the eucharist, and absolution, as sacraments.

1896.  J. H. Wylie, Hist. Eng. Hen. IV., III. 388. Instead of schism, *tri-schism, which threatened to become centi-schism.

1887.  Morris, Odyss., V. 292. His hand the *tri-spear grasping.

  III.  5. In Chemical nomenclature, in the names of compounds and derivatives, with general sense ‘three,’ ‘three times.’

  a.  Prefixed to names of compounds of elements, radicals, or groups, names of salts, etc., to signify three atoms, groups, or equivalents of these elements or radicals in combination with another element or radical; e.g., tribromide, a compound of 3 atoms of bromine with another element or radical, as tribromide of boron; trisulphate, a compound of three SO₄ groups with a metal or radical (or in earlier nomenclature of three SO₃ groups with a basic oxide). So trichloride, -cyanide, -fluoride, -hydride, -iodide, -oxide, -sulphide (-sulphuret); triacetate, -carbonate, -chlorate, -cyanate, -hydrate, -phosphate, -thionate, etc. Also in names of some organic compounds, referring to their composition, as TRIAMIDE, TRIAMINE, and the compound ethers or esters of glycerin with acids, as TRIACETIN, tributyrin, -palmitin, -stearin, etc. See also TRISILICATE.

  In early nomenclature, tri- or tris- prefixed to the name of a salt meant 3 molecules not of the acid, but of the base; thus 3 PbO.C₄H₅O₃ was called tris- or tri-acetate of lead; similarly B₃O was called trioxide of any element B.

1826.  Henry, Elem. Chem., I. 591. Tri-phosphate of lime.

1850.  Daubeny, Atomic Theory (ed. 2), 112. When the number of proportionals of base is 2, the prefix di or dis is adopted; when 3, tris; when four, tetrakis.… trisilicate of iron, 3 of base to 1 of silicic acid.

1860.  Scoffern, Orr’s Circle of Sciences, Chem. (new ed.), 467. The most important is the tris or triacetate [of lead].

1856.  Fownes, Chem. (ed. 6), 607. Three compounds of stearic acid with glycerin … which M. Berthelot distinguishes as monostearin, bistearin, and tristearin.

1863–72.  Watts, Dict. Chem., I. 895. The metals which form trichlorides are antimony, arsenic, bismuth, gold, molybdenum, thallium, vanadium, and probably indium.

1866.  Roscoe, Elem. Chem., xvi. 142. Arsenic unites with chlorine, bromine, and iodine, to form arsenic trichloride, tribromide, and triiodide. Ibid., xxiv. 207. Metallic antimony occurs native, but its chief ore is the trisulphide.

  b.  Prefixed to adjs., or to sbs. used attrib., in the names or descriptions of acids, alcohols, compound ethers or esters, oxides, salts, etc.; e.g., trisodic or trisodium, (a salt) containing 3 atoms of sodium; triethylic or triethyl (a compound) containing 3 ethyl groups. So trihydric or trihydrogen, tricalcic or tricalcium, triargentic or tri-silver, tricarbon, trichloric, trimethylic or trimethyl, triplumbic, trithionic, triacetic, etc.

1866.  Odling, Anim. Chem., 108. We meet with still less oxidised tricarbon molecules.

1869.  Roscoe, Elem. Chem., xv. 154. The three atoms of hydrogen in trihydrogen phosphate may be replaced by three different metals.

1873.  Watts, Fownes’ Chem., 340. A trisodic orthophosphate, sometimes called subphosphate. Ibid., 451. Triplumbic tetroxide, or Red lead.

1888.  Muir & Morley, Watts’ Dict. Chem., I. 99. Alcohols are classed as monohydric, dihydric, trihydric … according to the number of hydroxyl-groups which they contain.

  c.  Prefixed to the names of elements or radicals, or their combining forms (as azo-, bromo-, chloro-, hydro-, hydroxy-, iodo-, nitro-, oxy-, sulpho-, thio-: see these) entering into the name of a compound, to signify that three atoms or groups of the element or radical are present, or are substituted for hydrogen, in the substance designated by the rest of the name: as tribromobenzene, C₆H₃Br₃, in which three of the hydrogen atoms of benzene, C₆H₆, are replaced by three bromine atoms; so trimethylbenzene, C₆H₃(CH₃)₃; triethylcarbinol, C(C₂H₅)₃OH; trimethylamine, N(CH₃)₃; trichlorhydrin, C₃H₅Cl₃; so tribromhydrin, etc. Combinations of this kind are formed when wanted, and are unlimited in number: only a few are mentioned in this work: see TRIBROM-, TRICHLOR-, etc.

  d.  In verbs and their pples. derived from sbs. as in a, as tribrominated, trichlorinated, in which three hydrogen atoms have been replaced by atoms of bromine or chlorine; trihydrated, containing three molecules of water.

1857.  Miller, Elem. Chem., III. 47. Trichlorinated Dutch Liquid.

1868.  Trihydrated: see TRIHYDRATE.

  IV.  6. Forming verbs (and derivatives), as TRI-FALLOW, TRISECT, TRISECTION, q.v.