FALSEHOOD Copy link • FALSEHOODs. Falseness, vanitas, or by circumlocution with adjectives; e.g., to prove the falsehood of anything, aliquid falsum esse probare (Quint.). ☞ Falsitas is not found till Arnobius; modern editors discard it from Cic., Cluent., 2. A false thing, falsum: vanum: mendacium (a lie): not to utter a falsehood, nihil falsi dicere; non mentiri; verum dicere. Vid: LIE.