- a colorless, highly volatile, flammable liquid, C4H10O, 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.
- (formerly) one of a class of compounds in which two organic groups are attached directly to an oxygen atom, having the general formula ROR.
- the upper regions of space; the clear sky; the heavens.
- the medium supposed by the ancients to fill the upper regions of space.
- a hypothetical substance supposed to occupy all space, postulated to account for the propagation of electromagnetic radiation through space.
- a colourless volatile highly flammable liquid with a characteristic sweetish odour, made by the reaction of sulphuric acid with ethanol: used as a solvent and anaesthetic. Formula: C 2 H 5 OC 2 H 5
- any of a class of organic compounds with the general formula ROR′ where R and R′ are alkyl groups, as in diethyl ether C 2 H 5 OC 2 H 5
- the hypothetical medium formerly believed to fill all space and to support the propagation of electromagnetic waves
- the upper regions of the atmosphere; clear sky or heaven
- a rare word for air
