1. Characterized by lightness and insubstantiality; intangible.
2. Highly refined; delicate. See synonyms at airy.
3. 1. Of the celestial spheres; heavenly.
   2. Not of this world; spiritual.
4. Chemistry. Of or relating to ether.

[From Latin aetherius, from Greek aitherios, from aithēr, upper air.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.