\E*the"re*ous\, a. [L. aethereus, Gr. ? See {Ether}.]
1. Formed of ether; ethereal. [Obs.]
         This ethereous mold whereon we stand. --Milton.
2. (Chem.) Pertaining to, or resembling, ether.
{Ethereous oil}. See {Ethereal oil}, under {Ethereal}.