τέρας , ατος and αος (cf. τεῖρος, ἀστήρ): prodigy, portent,
omen, found in some manifestation of nature, such as
thunder, lightning, the rainbow. τέρας
Διός, ‘sent by Zeus,’ Il. 12.209
; ἀνθρώπων, ‘for
men,’ Il. 11.28; of a
monster, the Gorgon, Il.
5.742.