WordNet sense 1 (open to or abounding in fresh air):

aired

WordNet sense 2 (not practical or realizable; speculative):

impractical, visionary, windy, laputan

WordNet sense 3 (of comparatively little physical weight or density):

light

WordNet sense 4 (characterized by lightness and insubstantiality; as impalpable or intangible as air):

aerial, ethereal, aeriform, aery, aerial

WordNet sense 5 (lacking material form or substance; unreal):

unreal, unsubstantial