[ether] n [ME, fr. L aether, fr. Gk aither, fr. aithein to ignite, blaze; akin to OE ad pyre--more at edify] (14c) 1 a: the rarefied element formerly believed to fill the upper regions of space b: the upper regions of space: heavens
2. a: a medium that in the wave theory of light permeates all space and transmits transverse waves b: airwaves 3 a: a light volatile flammable liquid used chiefly as a solvent and anesthetic b: any of various organic compounds characterized by an oxygen atom attached to two carbon atoms -- ethe.ric adj