Abbott-Smith Manual Greek Lexicon
Ἀβαδδών (G3)
1 Ἀβαδδών (Heb. אֲבַדֹּון , destruction ; LXX, ἀπώλεια , only in Wisdom Lit., of the place of the ruined dead: Jb 26:6 , 28:22 , 31:12 , Ps 88:12 , Pr 15:11 *), indecl.; in NT, Abaddon , the angel of the Abyss: Re 9:11 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain