aery -
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"
unsubstantial,
insubstantial,
unreal lacking material form or substance; unreal; "as insubstantial as a dream"; "an insubstantial mirage on the horizon"
