aeriform, aerial, airy, aery, ethereal -- (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")
ethereal -- (of or containing or dissolved in ether; "ethereal solution")
celestial, ethereal, supernal -- (of heaven or the spirit; "celestial peace"; "ethereal melodies"; "the supernal happiness of a quiet death")
ethereal, gossamer -- (characterized by unusual lightness and delicacy; "this smallest and most ethereal of birds"; "gossamer shading through his playing")
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