ὀλέθρ-ιος · olethr-ios — LSJ
destructive, deadly, ὀ. ἦμαρ the day of destruction, Il. 19.294, 409, cf. ἐλεύθερον ἦμαρ, etc. ; so μανίη πάγχυ ὀ. Hdt. l.c. ; ὀ. μόρος A. Th. 704 ; ἔξω κομίζων ὀλεθρίου πηλοῦ πόδα Id. Ch. 697 ; κότος ὀ. ib. 952 (lyr.) ; ὀλεθρία νύξ S. OC 1683 (lyr.), etc. ; ψῆφος ὀλεθρία a vote of death, A. Th. 198 : in S. Aj. 799, ἔξοδον . . ὀλεθρίαν ἐλπίζει φέρειν seems to be = φέρειν εἰς ὄλεθρον : acc. sg. masc. predicatively used, ἀλλά μʼ ἁ . . θεὸς ὀλέθριον αἰκίζει fatally, ib. 402 (lyr.) :—rare in Prose,
c. gen., γάμοι Πάριδος ὀλέθριοι φίλων bringing ruin on his friends, A. Ag. 1156 (lyr.).
c. dat., as Subst., ψύλλοις ὀλέθριον, name of a fluid, Philum. Ven. 12.4.
of persons, in danger of death, Hp. Acut. 58 ; lost, undone, S. Tr. 878. Adv. -ίως, ἔχειν Gal. 16.522, al.
rascally, worthless (cf. ὄλεθρος II nisi hoc leg.), Luc. DMort. 3[2].1 codd., Hist.Conscr. 38 codd. ὀλεθρ-ιώδης, ες, gloss on λευγαλέη, Hsch.