Eng., "air," signifies "the atmosphere," certainly in five of the seven occurrences, Act 22:23, 1Co 9:26, 1Co 14:9, Rev 9:2, Rev 16:17, and almost certainly in the other two, Eph 2:2, 1Th 4:17.
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denotes "the heaven." The RV always renders it "heaven." The AV translates it "air" in Mat 8:20. In the phrase "the fowls (or birds) of the heaven" the AV always has "air;" "sky" in Mat 1:16-3, Luk 12:56; in all other instances "heaven." The word is probably derived from a root meaning to cover or encompass. See HEAVEN, SKY.