ἀήρ

Etymology
Beekes gives, from , from. Cognate with (< ), 🇨🇬. The a was lengthened to ā by compensatory lengthening.

Sihler gives but provides no further etymology. See 🇨🇬.

Noun

 * 1) mist
 * 2) air
 * 3) wind
 * 4) space, volume
 * 5) blue or grey (the colour of the sky)