τέρας
I. "a sign, wonder, marvel", Lat. portentum, prodigium, Hom.; esp. of signs in heaven, Il. (cf. τεῖρος), etc.
II. in concrete sense, "a monster", Διὸς τ. αἰγιόχοιο, of the Gorgon's head, id=Il.; of a serpent, id=Il.; of Typhoeus, Aesch.; of Cerberus, Soph.