What is the Latin word for two?

The usual Latin words for “two” are duo, bīni, biduus; also biennium, bīmus, biennis. The right choice depends on the sense; see the distinctions below.

English → Latin

“two” in Latin

duotwo; 2 bīniTwo by two biduusContinuing for two days bienniuma period of two years, biennium bīmustwo-year-old; lasting two years biennistwo-year-old; of two years, lasting two years

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

two

duo, bini (distributive, or with substantive found only in the plur.; Vid: TWELVE). Two days, biduum: two years, biennium: of two years, bimus: bimulus: duos annos natus (two years old): ☞ biennalis is unclassical; biennis is doubtful; for, instead of bienni, ap. Suet., Galb., 15, the last modern editions read biennii. Of two months, bimensis; bimestris: two pounds weight, duo pondo: duas libras pondo (valens): of two pounds weight, bilibris: two and a half, duo semis, duo et semis: two ases and a half, sestertius: two feet and a half broad, latus pedes duos semis: he does not know how many twice two make, non didicit bis bina quot sint: in two, ruptus (broken): fractus (broken with violence): scissus (cleft, rent); or by verbs, especially with dis; as, to break in two, frangere, diffringere; to strike in two, discutere; to cut in two, dissecare; to be in two, ruptum or fractum esse: dehiscere, hiare (to have a chink). To do two things at once; kill two birds with one stone (proverbial), de eadem fidelia duos parietes dealbare (Curt., Cic., Ep.).

Quick answer

What is the Latin word for two?: The usual Latin words for “two” are duo, bīni, biduus; also biennium, bīmus, biennis. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.