interfectōrius, a, um, adj. interfector, deadly, murderous (late Lat.), Aug. de Lib. Arb. 3, 25; Isid. Orig. 17, 7, 7.

— Subst.: interfectōrium, i, n., a means of destruction, Ambros. de Elia et Jejun. 10, 37 fin.

—Hence, adv.: interfectōriē, destructively, murderously, Aug. contr. Parm. 3, 2, 14.