ἀήρ, ἀέρος, ὁ,
[in LXX: 2Ki.22:12 (= Psa.17(18):11 שׁחק), Wi .8 ;]
in Hom., Hes., the lower air which surrounds the earth, as opposite to the purer αἰθήρ of the higher regions; generally, air (MM, VGT, see word): Act.22:23, 1Th.4:17, Rev.9:2 16:17; of the air as the realm of demons, Eph.2:2; ἀ. δέρειν, of striving to no purpose, 1Co.9:26; εἰς ἀ. λαλεῖν, of speaking without effect, not being understood, 1Co.14:9.†
(AS)