ether: Meaning and Definition of

e•ther

1. a colorless, highly volatile, flammable liquid, CHO, 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. (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. a hypothetical substance supposed to occupy all space, postulated to account for the propagation of electromagnetic radiation through space. Cf. Michelson-Morley experiment.