aeriform in WordNet English dictionary

1. characterized by lightness and insubstantiality; as impalpable or intangible as air
   "figures light and aeriform come unlooked for and melt away"- Thomas Carlyle; "aerial fancies"; "an airy apparition"; "physical rather than ethereal forms"
   aeriform  aerial  airy  aery  ethereal 
   
2. resembling air or having the form of air
   aeriform  airlike