mendax, dācis, adj. [mentior], given to lying, mendacious; subst., a liar.
I Lit.: mendacem esse adversus aliquem, Plaut. Poen. 1, 2, 188: cum mendaci homini, ne verum quidem dicenti, credere soleamus, Cic. Div. 2, 71, 146: Carthaginienses fraudulenti et mendaces, id. Agr. 2, 35, 95: aretalogus, Juv. 15, 16.—As subst.: mendax , dācis, m., a liar .—Prov.: mendacem memorem esse oportet, a liar should have a good memory , Quint. 4, 2, 91.— Comp. : Parthis mendacior, Hor. Ep. 2, 1, 112.— Sup. : mendacissimus, the greatest liar , Plaut. Rud. 3, 4, 48.—With gen.: si hujus rei me mendacem esse inveneris, Plaut. As. 5, 2, 4.—With dat.: saepe fui mendax pro te mihi, Ov. H. 2, 11.—With in and acc.: in parentem, Hor. C. 3, 11, 35; for which adversum , Plaut. Poen. 1, 2, 188.— With in and abl.: in tenui farragine, Pers. 5, 77.—
II Transf., of inanim, and abstr. things, lying, false, deceptive; feigned, fictitious, counterfeit, not real , etc. (mostly poet.): mendacia visa, Cic. Div. 2, 62, 127: speculum, Ov. Tr. 3, 7, 38: fundus, that does not yield the expected fruits , Hor. C. 3, 1, 30: damnum, Ov. A. A. 1, 431: infamia, Hor. Ep. 1, 16, 39: os, Tib. 3, 6, 35: pennae, Ov. M. 10, 159: quidquid Graecia mendax audet in historia, Juv. 10, 174.—Hence, adv.: mendācĭter , falsely, mendaciously (post-class.): praedicare, Sol. 1, 87.— Sup. : mendacissime dicere, Aug. Mor. Eccl. 1, 17.