Ethereous \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.

Source: Webster's Revised Unabridged Dictionary (1913)