I.gen. plur. fallacium, Cic. Lael. 25, 91 al.; “but fallacum,” Cat. 30, 4), adj. fallo, deceitful, deceptive, fallacious (class.; esp. freq. in Cic.; “syn.: captiosus, fraudulentus, subdolus, dolosus, vafer, astutus, callidus): age, barbari (astrologi) vani atque fallaces: num etiam Graiorum historia mentita est?” Cic. Div. 1, 19, 37: “levium hominum atque fallacium,” id. Lael. 25, 91; “for which: facta impia fallacum hominum,” Cat. 30, 4: “vicinitas non assueta mendaciis, non fucosa, non fallax, non erudita artificio simulationis,” Cic. Planc. 9, 22: “posita fallacis imagine tauri,” Ov. M. 3, 1 et saep.—Of inanim. and abstr. things: “ut tamquam in herbis non fallacibus fructus appareat,” Cic. Lael. 19, 68: “(with fucosae) merces,” id. Rab. Post. 14, 40: “arva,” Ov. A. A. 1, 401: “siliquae,” Verg. G. 1, 195: “austri,” id. A. 5, 850: “herba veneni,” id. E. 4, 24: “vada,” Plin. 5, 31, 34, § 128: “genus tutius sed magis fallax (sc. venandi),” more uncertain, id. 8, 8, 8, § 26 et saep.: “spe falsa atque fallaci,” Cic. Phil. 12, 2 fin.; so, “spes,” id. Mil. 34, 94: “et captiosae interrogationes,” id. Ac. 2, 15, 46: “imitatio simulatioque virtutis,” id. ib. 2, 46, 140: “malitia est versuta et fallax nocendi ratio,” id. N. D. 3, 30, 75.—Prov.: fallaces sunt rerum species, Sen. Ben. 4, 34, 1.— Comp.: “fallacior undis,” Ov. M. 13, 799: “quid enim fallacius illis (vocibus)?” id. R. Am. 687.—Sup.: “oculorum fallacissimo sensu judicare,” Cic. Div. 2, 43, 91.—
(γ).
With dat.: “Planasia navigiis fallax,” Plin. 3, 6, 12, § 80.—Hence, adv.: fallācĭter , deceitfully, fallaciously (cf.: “falso, perperam): ratio hoc postulat, ne quid insidiose, ne quid simulate, ne quid fallaciter,” Cic. Off. 3, 17, 68; id. Div. 1, 18, 35; id. Part. Or. 25, 90.—Sup.: “fallacissime,” Plin. 12, 16, 35, § 71.