Abbott-Smith Manual Greek Lexicon
ὀλέθριος (G3639)
4 ὀλέθριος , -ον (also -α, -ον , as in Wi 18:15 ), [in LXX : III Ki 21 (20):42 ( חֵרָם ), Wi 18:15 *;] destructive , deadly : δίκην , II Th 1:9 , L, txt. (for ὄλεθρος , q.v.).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain