Abbott-Smith Manual Greek Lexicon
ἀΐδιος (G126)
2 ** ἀΐδιος , -ον ( ἀεί ), [in LXX: Wi 7:26 , IV Mac 10:15 *;] everlasting (freq. in Inscr.; MM, VGT , s.v.): Ro 1:20 , Ju 6 .† SYN. : αἰώνιος , also freq. in Inscr. (Deiss., BS , 363 J. The etymological distinction between the meanings of the two words seems not to be retained in late Greek (v. Thayer, s.v., αἰώνιος ; cf. Cremer, 79, 611).
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain