mendācĭum, ii, n. [mendax], a lie, untruth, falsehood.
I Lit. (class.): dicere alicui mendacium de re aliquā, Plaut. Bacch. 4, 9, 33: mendacio fallere, Cic. Mur. 30, 62: vatum, Ov. F. 6, 253: famae, id. ib. 4, 311: immensa spirant mendacia, Juv. 7, 111: Titiae meae, cum quā sine mendacio vixi, i. e. honestly, without hypocrisy , Dig. 34, 2, 36: prophetāsti mendacium, Vulg. Jer. 20, 6; cf. id. ib. 27, 10: credere mendacio, to believe a lie , id. 2 Thess. 2, 11.—
B Esp., a fable, fiction (opp. historic truth): poëtarum, Curt. 3, 1, 4.—
II Transf., of things, a counterfeit (post-Aug.): neque est imitabilior alia mendacio vitri, Plin. 37, 8, 33, § 112; 35, 6, 29, § 48.