What is the Latin word for liar?

The usual Latin words for “liar” are mendāx, mentior. The right choice depends on the sense; see the distinctions below.

English → Latin

“liar” in Latin

mendāxmendacious (lying, untruthful, dishonest)mentiorto lie, cheat, deceive; to pretend, feign

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

liar

homo mendax; mendax. Call me 1iar, if, etc., mentiar, si, etc.: a liar ought to have a good memory, mendacem memorem esse oportet (Quint., 4, 2, 91; Apul., Apol., p. 318, 32).

Quick answer

What is the Latin word for liar?: The usual Latin words for “liar” are mendāx, mentior. 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.