Main Entry: ether

Pronunciation: \ˈē-thər\

Function: noun

Etymology: Middle English, from Latin aether, from Greek aithēr, from aithein to ignite, blaze; akin to Old English ād pyre — more at edify

Date: 14th century

1 a : the rarefied element formerly believed to fill the upper regions of space b : the upper regions of space : heavens
2 aalso ae·ther : a medium that in the wave theory of light permeates all space and transmits transverse waves b : airwaves
3 a : a light volatile flammable liquid C₄H₁₀O used chiefly as a solvent and especially formerly as an anesthetic b : any of a class of organic compounds characterized by an oxygen atom attached to two carbon atoms

— ethe·ric \i-ˈther-ik, -ˈthir-\ adjective