Lexicon :: Strong's G109 - aēr

ἀήρ, ἀέρος, ὁ, (ἄημι, ἄω, [cf. ἄνεμος, at the beginning]), the air (particularly the lower and denser, as distinguished from the higher and rarer ὁ αἰθήρ, cf. Homer, Iliad 14, 288), the atmospheric region: Acts 22:23; 1 Thessalonians 4:17; Revelation 9:2; Revelation 16:17; ὁ ἄρχων τῆς ἐξουσίας τοῦ ἀέρος in Ephesians 2:2 signifies 'the ruler of the powers (spirits, see ἐξουσία 4 c. ββ.) in the air,' i. e. the devil, the prince of the demons that according to Jewish opinion fill the realm of air (cf. Meyer at the passage; [B. D. American edition under the word Air; Stuart in Bib. Sacr. for 1843, p. 139f]). Sometimes indeed, ἀήρ denotes a hazy, obscure atmosphere (Homer, Iliad 17, 644; 3, 381; 5, 356, etc.; Polybius 18, 3, 7), but is nowhere quite equiv, to σκότος, — the sense which many injudiciously assign it in Ephesians, the passage cited ἀέρα δέρειν, (cf. verberat ictibus auras, Vergil Aen. 5, 377, of pugilists who miss their aim) i. e. to contend in vain, 1 Corinthians 9:26; εἰς ἀέρα λαλεῖν (verba ventis profundere, Lucr. 4, 929 (932)) 'to speak into the air' i. e. without effect, used of those who speak what is not understood by the hearers, 1 Corinthians 14:9.

BLB Scripture Index of Thayer's