ether meaning and definition

ETHER noun

Definition of ether (noun)

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