| The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.|
Derivatives include three, trio, testicle, detest, and trinity.
I. Nominative plural form *treyes. 1a. three, thrice; thirteen, thirty, from Old English thre, thro, thr, three, with its derivatives thrga, thrwa, thrice, thrtig, thirty, and throtne, thirteen (-tne, ten; see dek); b. trillium, from Old Swedish thrr, three. Both a and b from Germanic *thrijiz. 2. trey; trammel, trecento, trephine, triumvir, trocar, from Latin trs, three. 3. triskaidekaphobia, from Greek treis, tris, three.
II. Zero-grade form *tri-. 1. Suffixed form *tri-tyo-. a. (i) third, from Old English thrid(d)a, thirdda, third; (ii) riding2, from Old Norse thridhi, third. Both (i) and (ii) from Germanic *thridjaz, third; b. tercel, tercet, tertian, tertiary, tierce; sesterce, from Latin tertius, third. 2. Combining form *tri-. a. tri-, tribe, trio, triple, from Latin tri-, three; b. tri-; triclinium, tricrotic, tridactyl, triglyph, tritone, from Greek tri-, three; c. Trimurti, from Sanskrit tri-, three. 3. triad, from Greek trias, the number three. 4. trichotomy, from Greek trikha, in three parts. 5. trierarch, from Greek compound trirs, galley with three banks of oars, trireme (-rs, oar; see er-). 6. Suffixed form *tri-to-. tritium, from Greek tritos, third. 7. Compound form *tri-pl-, threefold (*-pl- < combining form *-plo-, -fold; see pel-2). triploblastic, from Greek triploos, triple. 8. Compound form *tri-plek-, threefold (*-plek-, -fold; see plek-). triplex, from Latin triplex, triple. 9. Compound form *tri-st-i-, third person standing by (-st-, standing; see st-). testament, testimony, testicle, testis; attest, contest, detest, obtest, protest, testify, from Latin testis, a witness. 10. sitar, teapoy, from Persian si, three.
III. Extended zero-grade form *tris, thrice. 1. tern2; terpolymer, from Latin ter, thrice. 2. trisoctahedron, Hermes Trismegistus, from Greek tris, thrice. 3. Suffixed form *tris-no-. trine, trinity, from Latin trn, three each.
IV. Suffixed o-grade form *troy-o-. troika, from Russian troje, group of three. (Pokorny trei- 1090.)
|The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company. Published by the Houghton Mifflin Company. All rights reserved.||