horrificus, a, um, adj. horror-facio, that causes tremor or terror, terrible, dreadful, frightful, horrific (poet. and in postAug. prose): bustum, Lucr. 3, 906: letum, Verg. A. 12, 851: ruinae (Aetnae), id. ib. 3, 571: lapsu (Harpyiarum), id. ib. 3, 225: fulmen, Val. Fl. 2, 97: acta, id. 3, 423: caesaries, Luc. 2, 372: poena, Gell. 20, 1 fin.

— Adv.: horrificē, in a manner to cause dread, with affright: horrifice fertur divinae Matris imago, Lucr. 2, 609; 4, 36.