ether Meaning, Definition & Usage

  1. noun the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies
    quintessence.
  2. noun any of a class of organic compounds that have two hydrocarbon groups linked by an oxygen atom
  3. noun a medium that was once supposed to fill all space and to support the propagation of electromagnetic waves
    aether.
  4. noun a colorless volatile highly inflammable liquid formerly used as an inhalation anesthetic
    divinyl ether; ethyl ether; diethyl ether; vinyl ether; ethoxyethane.

WordNet

E"ther noun
Etymology
L. aether, Gr. , fr. to light up, kindle, burn, blaze; akin to Skr. idh, indh, and prob. to E. idle: cf. F. éther.
Definitions
  1. (Physics) A medium of great elasticity and extreme tenuity, supposed to pervade all space, the interior of solid bodies not excepted, and to be the medium of transmission of light and heat; hence often called luminiferous ether.
  2. Supposed matter above the air; the air itself.
  3. (Chem.) (a) A light, volatile, mobile, inflammable liquid, (C2H5)2O, of a characteristic aromatic odor, obtained by the distillation of alcohol with sulphuric acid, and hence called also sulphuric ether. It is powerful solvent of fats, resins, and pyroxylin, but finds its chief use as an anæsthetic. Called also ethyl oxide. also commonly, ethyl ether. (b) Any similar oxide of hydrocarbon radicals; as, amyl ether; valeric ether.

Webster 1913