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