(adj.adv.) : nĕfandus, a, um, adj.ne-fari, lit. not to be mentioned, unmentionable; hence
* Impious, heinous, execrable, abominable (mostly post-Aug.; syn. infandus): sperate deos memores fandi atque nefandi,i. e. wrong, impiety,Verg. A. 1, 543: nefandum adulterium, Cic. Fragm. ap. Quint. 5, 11, 12 (al. nefarium): nefandum vehiculum,Liv. 1, 59: nefandissima quaeque tyrannicae crudelitatis exercuit,Just. 16, 4, 11: fraus,Juv. 13, 174: sacri,id. 15, 116.—Of persons: homo nefandus,Plin. 28, 1, 2, § 9: nefandi homines,Quint. 1, 3, 17.—Sup.: aususne es, nefandissimum caput? etc.,Just. 18, 7, 10.—Hence, adv.: nĕfandē, impiously: multa nefande ausi, Sall. Fragm. ap. Prisc. p. 993 P. (dub: Dietsch. H. 1, 62, nefanda).—Sup.: nefandissime,Cassiod. Hist. Eccl. 10, 28.

s. TLL