| Language | Reflex(es) | Gloss | Grammar | Sources |
|---|
| English |
| English | triskaidekaphobia | abnormal fear of number 13 | n | AHD LRC |
| English | trigeminus | main facial sensory nerve | n | AHD LRC |
| English | Thrihyrne | Helm's Deep mountain in Tolkien: The Lord of the Rings | prop.n | LRC |
| English | triceratops | herbivorous dinosaur of Cretaceous Period | n | AHD LRC |
| English | tricrotic | re: triple beat in arterial pulse | adj | AHD W7 LRC |
| English | tricrotism | having 3 pulse beats per heartbeat | n | AHD LRC |
| English | triquetrous | triangular, having three acute angles | adj | AHD W7 LRC |
| English | triquetrum | wedge-shaped carpal bone | n | AHD LRC |
| English | Thrimidge, Thrimi(l)ch | Shire calendar's May in Tolkien: The Lord of the Rings | prop.n | LRC |
| English | trisoctahedron | regular solid with 24 congruent faces | n | AHD W7 LRC |
| English | tripedal | having 3 feet | adj | AHD LRC |
| English | threefold | triple, 3 times the number/quantity | adj | W7 LRC |
| English | trimer | three identical molecules combined | n | AHD LRC |
| English | attest | to affirm as true/genuine | vb | AHD W7 LRC |
| English | contest | to make subject of dispute/contention/litigation | vb | AHD W7 LRC |
| English | detest | to loathe, abhor, dislike intensely | vb.trans | AHD W7 LRC |
| English | obtest | to beseech, supplicate | vb | AHD W7 LRC |
| English | protest | to avow, make solemn declaration/affirmation of | vb | AHD W7 LRC |
| English | riding | administrative jurisdiction in Yorkshire, England | n | AHD W7 LRC |
| English | sesterce | ancient Roman coin: 1/4 denarius | n | AHD W7 LRC |
| English | tercel | male hawk/falcon | n | AHD LRC |
| English | tern | type of sea gull | n | AHD W7 LRC |
| English | terpolymer | polymer of 3 distinct monomers | n | AHD LRC |
| English | tertian | recurring at ca. 3-day intervals | adj | AHD W7 LRC |
| English | tertiary | of 3d rank/value/importance | adj | AHD W7 LRC |
| English | tertiary | member of of monastic 3rd order | n | AHD W7 LRC |
| English | testament | covenant between God and man | n | AHD W7 LRC |
| English | testicle | testis | n | AHD W7 LRC |
| English | testify | to bear witness, make statement based on personal belief/knowledge | vb | AHD W7 LRC |
| English | testimony | (ark containing) tablets inscribed with Mosaic law | n | AHD W7 LRC |
| English | testis | male reproductive gland | n | AHD W7 LRC |
| English | third | 3rd (in place/time) | nbr.ord | AHD W7 LRC |
| English | thirty | 30 | nbr.card | AHD W7 LRC |
| English | three | 3 | nbr.card | AHD W7 LRC |
| English | thrice | three times | adv | AHD W7 LRC |
| English | tierce | third (3rd) | nbr.ord | AHD W7 LRC |
| English | trey | side of die/domino with 3 spots | n | AHD W7 LRC |
| English | tri- | three | pfx | AHD W7 LRC |
| English | triad | trinity, group/union of three | n | AHD W7 LRC |
| English | tribe | social group comprising relatives/adoptees/slaves | n | AHD W7 LRC |
| English | trichotomy | division into 3 parts/classes/elements | n | AHD W7 LRC |
| English | tridactyl | having 3 fingers/toes | adj | AHD W7 LRC |
| English | triglyph | 3-grooved tablet in Doric frieze | n | AHD W7 LRC |
| English | trillium | lily with erect stem bearing 3 leaves | n | AHD W7 LRC |
| English | Trimurti | triad of gods: Brahma, Vishnu, Shiva (Hinduism) | prop.n | LRC |
| English | trine | triple, threefold | adj | AHD W7 LRC |
| English | trinity | triad, three in one | n | AHD W7 LRC |
| English | trio | group of three | n | AHD W7 LRC |
| English | triple | having 3 units/members | adj | W7 LRC |
| English | triplex | triple, threefold | adj | AHD W7 LRC |
| English | tritium | radioactive hydrogen isotope with 3 times ordinary mass | n | AHD W7 LRC |
| English | tritone | musical interval: three whole steps | n | AHD W7 LRC |
| English | troika | Russian vehicle pulled by 3 horses abreast | n | AHD W7 LRC |
| Old English | þri-milce | May, lit. three-milkings (month) | n.masc | ASD LRC |
| Old English | þirdda, þridda | third (3rd) | nbr.ord | W7 LRC |
| Old English | þridding | doing something for 3rd time | n.fem | W7 LRC |
| Old English | þrīe, þrēo, þrēo | three (3) | nbr.card | LRC |
| Old English | þri-feald | threefold | adj | ASD LRC |
| Old English | þriga | thrice | adv | W7 LRC |
| Old English | þrītig, þrittig | thirty (30) | nbr.card | ASD LRC |
| Middle English | detesten | to detest | vb | W7 LRC |
| Middle English | protesten | to protest | vb | W7 LRC |
| Middle English | riding | riding | n | W7 LRC |
| Middle English | terce | tierce | nbr.ord | W7 LRC |
| Middle English | tercian | tertian | adj | W7 LRC |
| Middle English | testament | testament | n | W7 LRC |
| Middle English | testicule | testicle | n | W7 LRC |
| Middle English | testifien | to testify | vb | W7 LRC |
| Middle English | testimony | testimony | n | W7 LRC |
| Middle English | thirde, thridde | third (3rd) | nbr.ord | W7 LRC |
| Middle English | three | three (3) | nbr.card | W7 LRC |
| Middle English | thrie(s) | thrice | adv | W7 LRC |
| Middle English | thritty | thirty (30) | nbr.card | W7 LRC |
| Middle English | tierce | tierce | nbr.ord | W7 LRC |
| Middle English | treis | trey | n | W7 LRC |
| Middle English | treye | trey | n | W7 LRC |
| Middle English | tri- | tri- | pfx | W7 LRC |
| Middle English | tribe | tribe | n | W7 LRC |
| Middle English | trine | trine | adj | W7 LRC |
| East Germanic |
| Crimean Gothic | *treiþien, treithyen | thirty (30), lit. third ten | nbr.card | CGo LRC |
| Crimean Gothic | *þiinetria, thune-tria | thirteen (10 + 3) | nbr.card | CGo GED LRC |
| Gothic | þreis, þreis, þrija | three (3) | nbr.card | LRC |
| Gothic | þridja | third (3rd) | nbr.ord | EIE LRC |
| Crimean Gothic | tria | three (3) | nbr.card | CGo LRC |
| Celtic |
| Old Irish | tri(ū) | three (3) | nbr.card | EIE LRC |
| Irish | trí | three (3) | nbr.card | LRC |
| Scots Gaelic | trì | three (3) | nbr.card | LRC |
| Manx | tree | three (3) | nbr.card | LRC |
| Welsh | tri | three (3) | nbr.card | EIE LRC |
| Welsh | trydydd | third (3rd) | nbr.ord | EIE LRC |
| West Germanic |
| Old Frisian | thrē, thria, thriu | three (3) | nbr.card | ASD LRC |
| Old Frisian | thredda | third (3rd) | nbr.ord | ASD LRC |
| Old Frisian | thria, thriia | thrice | adv | W7 ASD LRC |
| Old Frisian | thrītich | thirty (30) | nbr.card | ASD LRC |
| Dutch | drie | three (3) | nbr.card | LRC |
| Old Saxon | thriddio | third (3rd) | nbr.ord | ASD LRC |
| Old Saxon | thrie, threa | three (3) | nbr.card | ASD LRC |
| Old Saxon | thriio, thriwo | thrice | adv | ASD LRC |
| Old Saxon | thrītig | thirty (30) | nbr.card | ASD LRC |
| Old Low German | thrie | three (3) | nbr.card | ASD LRC |
| Old Low German | thrīo | thrice | adv | ASD LRC |
| Old High German | drī, drīo, driu | three (3) | nbr.card | W7 ASD LRC |
| Old High German | dritt(i)o | third (3rd) | nbr.ord | EIE LRC |
| Old High German | drīzug | thirty (30) | nbr.card | ASD LRC |
| Middle High German | drīes | thrice | adv | EIE LRC |
| German | drei | three (3) | nbr.card | LRC |
| German | dreimal | thrice | adv | LRC |
| German | dritte | third (3rd) | nbr.ord | LRC |
| North Germanic |
| Old Norse | þriði | third (3rd) | nbr.ord | W7 LRC |
| Old Norse | þriðjungr | third part | n | W7 LRC |
| Old Norse | þrír, þrjár, þrjú | three (3) | nbr.card | LRC |
| Icelandic | þriþi | third (3rd) | nbr.ord | ASD LRC |
| Icelandic | þrír, þrjár, þrjú | three (3) | nbr.card | ASD LRC |
| Danish | terne | tern, sea-swallow | n | W7 DEO LRC |
| Danish | tre | three (3) | nbr.card | LRC |
| Swedish | tre | three (3) | nbr.card | LRC |
| Italic |
| Umbrian | terti(u) | third (3rd) | nbr.ord | EIE LRC |
| Latin | attestor, attestari | to prove, confirm, attest | vb.dep | W7 LRC |
| Latin | contestor, contestari | to call as witness | vb.dep | W7 LRC |
| Latin | destestor, detestari | to curse while calling on deity as witness | vb.dep | W7 LRC |
| Latin | obtestor, obtestari | to beseech, call to witness | vb.dep | W7 LRC |
| Latin | protestor, protestari | to witness before jury | vb.dep | W7 LRC |
| Latin | sestertius | two and a half times as great | adj | W7 LRC |
| Latin | ter | thrice | adv | LRC |
| Latin | tertianus | of the third | adj | W7 LRC |
| Latin | tertiarius | of a third | adj | W7 LRC |
| Latin | tertius | third (3rd) | nbr.ord | W7 LRC |
| Latin | testamentum | will, covenant | n.neut | W7 LRC |
| Latin | testiculus | testicle | n.masc | W7 LRC |
| Latin | testificor, testificari | to testify | vb.dep | W7 LRC |
| Latin | testimonium | evidence, witness | n.neut | W7 LRC |
| Latin | testis | witness: 3rd party to transaction | n.masc | W7 LRC |
| Latin | testor, testari | to bear witness, give evidence | vb.dep | W7 LRC |
| Latin | trēs | three (3) | nbr.card | W7 LRC |
| Latin | tri- | three | pfx | W7 LRC |
| Latin | triad- | group of three | pfx | W7 LRC |
| Latin | trias | triad | n.fem | W7 LRC |
| Latin | tribus | tribe, division of (Roman) people | n.fem | W7 LRC |
| Latin | triglyphus | triglyph | n.masc | W7 LRC |
| Latin | trini | three each | adv | W7 LRC |
| Latin | trinus | of three | adj | W7 LRC |
| Latin | triplex | threefold | adj | W7 LRC |
| Late Latin | testamentum | covenant with God, holy scripture | n.neut | W7 LRC |
| Late Latin | testimonium | testimony, Decalogue | n.neut | W7 LRC |
| Medieval Latin | tertiarius | of a third | adj | W7 LRC |
| New Latin | trillium | genus of herbs | n.neut | W7 LRC |
| New Latin | tritium | radioactive hydrogen isotope | n.neut | W7 LRC |
| Portuguese | attestar | to attest | vb | CDC LRC |
| Spanish | atestar | to attest | vb | CDC LRC |
| Old French | atester | to attest | vb | CDC LRC |
| Middle French | attester | to attest | vb | W7 LRC |
| Middle French | contester | to contest | vb | W7 LRC |
| Middle French | obtester | to obtest | vb | W7 LRC |
| Middle French | protester | to protest | vb | W7 LRC |
| Middle French | terz | third (3rd) | nbr.ord | W7 LRC |
| Middle French | tierce | third (3rd) | nbr.ord | W7 LRC |
| Middle French | treie | three (3) | nbr | W7 LRC |
| Middle French | treis | three (3) | nbr | W7 LRC |
| Middle French | trin | of three | adj | W7 LRC |
| French | attester | to attest | vb | CDC LRC |
| French | trio | trio | n.masc | W7 LRC |
| French | trois | three (3) | nbr.card | W7 LRC |
| Italian | attestare | to attest | vb | CDC LRC |
| Italian | tri- | three | pfx | W7 LRC |
| Italian | trio | trio, set of three | n.masc | W7 LRC |
| Balto-Slavic |
| Old Prussian | tīrts, tirts | third (3rd) | nbr.ord | EIE LRC |
| Old Prussian | tris | three (3) | nbr.card | EIE LRC |
| Lithuanian | trẽčias, trečià | third (3rd) | nbr.ord | LRC |
| Lithuanian | trỹs | three (3) | nbr.card | EIE LRC |
| Latvian | trešaĩs | third (3rd) | nbr.ord | EIE LRC |
| Latvian | trîs | three (3) | nbr.card | EIE LRC |
| Russian | trétij | third (3rd) | nbr.ord | EIE LRC |
| Russian | troe | three (3) | nbr.card | W7 LRC |
| Old Church Slavonic | tretijĭ, treti | third (3rd) | nbr.ord | EIE LRC |
| Old Church Slavonic | trьe, tri, tri | three (3) | nbr.card | LRC |
| Paleo-Balkan |
| Albanian | tre | three (3) | nbr.card | EIE LRC |
| Albanian | tretë | third (3rd) | nbr.ord | EIE LRC |
| Hellenic |
| Mycenaean | *tri- | three (3) | nbr.card | EIE LRC |
| Mycenaean | ti-ri-po | tripod | n | EIE LRC |
| Homeric Greek | τρεῖς, τριάς, τρία | three (3) | nbr.card | LRC |
| Homeric Greek | τριάκοντα | thirty (30) | nbr.card | LRC |
| Homeric Greek | τρίτατος | third (3rd) | nbr.ord | EIE LRC |
| Greek | τρῐ- | three, thrice | pfx | LS LRC |
| Greek | τρί-γλῠφος | triglyphic, lit. thrice-cloven | adj | LS LRC |
| Greek | τρῐ-δακτῠλος | tridactyl | adj | LS LRC |
| Greek | τρίς | thrice | adv | LS LRC |
| Greek | τρίτος | third (3rd) | nbr.ord | LRC |
| Anatolian |
| Lycian | tri- | three (3) | nbr.card | EIE LRC |
| Lycian | tri- | three (3) | nbr.card | LRC |
| Hittite | teri- | three (3) | nbr.card | LRC |
| Hittite | teriyan | third (3rd) | nbr.ord | EIE LRC |
| Armenian |
| Armenian | erek' | three (3) | nbr.card | LRC |
| Indo-Iranian |
| Avestan | θrayō | three (3) | nbr.card | EIE LRC |
| Avestan | θriš | thrice | adv | EIE LRC |
| Avestan | θritya- | third (3rd) | nbr.ord | EIE LRC |
| Sanskrit | tráyas, trī́ | three (3) | nbr.card | EIE LRC |
| Sanskrit | tritá, tr̊tíya- | third (3rd) | nbr.ord | EIE LRC |
| Sanskrit | trimūrti | having three forms, re: Trimurti | adj | W7 LRC |
| Sanskrit | triṣ, triḥ | thrice | adv | EIE LRC |
| Tocharian |
| Tocharian B | trai, tarya | three (3) | nbr.card | EIE LRC |
| Tocharian B | trite | third (3rd) | nbr.ord | EIE LRC |
| Tocharian A | tre | three (3) | nbr.card | EIE LRC |
| Tocharian A | trit | third (3rd) | nbr.ord | EIE LRC |