characterized by lightness and insubstantiality; as impalpable or intangible as air
<adj.all> figures light and aeriform come unlooked for and melt away aerial fancies an airy apparition physical rather than ethereal forms
Aeriform \A"["e]r*i*form\ (?; 277), a. [L. a["e]r air + -form: cf. F. a['e]riforme.] Having the form or nature of air, or of an elastic fluid; gaseous. Hence fig.: Unreal.