Definition of Ether

Noun: ether ee-thu(r)

Any of a class of organic compounds that have two hydrocarbon groups linked by an oxygen atom
A medium that was once supposed to fill all space and to support the propagation of electromagnetic waves
- aether
A colourless volatile highly inflammable liquid formerly used as an inhalation anaesthetic
- ethoxyethane, divinyl ether, vinyl ether, diethyl ether, ethyl ether
[archaic] The fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies
- quintessence [archaic]