What is the Latin word for either?

The usual Latin words for “either” are alteruter, uterus, uterlibet; also utervīs, volō. The right choice depends on the sense; see the distinctions below.

English → Latin

“either” in Latin

alteruterone of two, one or the other; either; = uterque, both uteruswomb, uterus; fetus, newborn; belly, paunch uterlibetWhichever of the two you please; either of the two utervīswhomever of the two you want, either of the two; whichever of the two you want, either of the two volōto wish, to please; to want; to mean, to intend

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

either

(of the two)(of the two), alteruter (either one or the other): uter, utercunque (mostly “which,” “whichever” of the two; but sometimes = “either;” e.g., si uter [orator et decumanus] velit): uterlibet: utervis (either of the two indifferently): utrum mavis (which of the two you choose). Nor did he wish to deprive the state of either army, neque rempublicam alterutro exercitu privare voluit: if any one had not been of either side, si qui non alteriusutrius partis fuisset: take or choose either, utrumlibet elige or utrum horum mavis accipe: in either way the consequence will be a great confusion, utrocunque modo summa sequetur confusio (Quint. 3, 6, 29). I have less strength than either of you, minus habeo virium, quam utervis vestrum: let either abuse the other, uterque utrumque vituperato. Not - either, neuter; on either (= each) side, alterutrimque (Plin., 20, 7, 26).

Quick answer

What is the Latin word for either?: The usual Latin words for “either” are alteruter, uterus, uterlibet; also utervīs, volō. 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.