— etheric /i ther"ik, i thear"-/ , adj.
/ee"theuhr/ , n.
1. Also called diethyl ether, diethyl oxide, ethyl ether, ethyl oxide, sulfuric ether . Chem., Pharm. a colorless, highly volatile, flammable liquid, C 4 H 10 O, having an aromatic odor and sweet, burning taste, derived from ethyl alcohol by the action of sulfuric acid: used as a solvent and, formerly, as an inhalant anesthetic.
2. Chem. (formerly) one of a class of compounds in which two organic groups are attached directly to an oxygen atom, having the general formula ROR.
3. the upper regions of space; the clear sky; the heavens.
4. the medium supposed by the ancients to fill the upper regions of space.
5. Physics. a hypothetical substance supposed to occupy all space, postulated to account for the propagation of electromagnetic radiation through space. Cf. Michelson-Morley experiment .
Also, aether (for defs. 3-5).
[ 1350-1400; ME aether the upper air, pure air, ether aithér, akin to aíthein to glow, burn, OE ad funeral pyre, L aestus heat ]