Ig″ne‐ous (?), a. [L. igneus, fr. ignis fire; allied to Skr. agni, Lith. ugnis, OSlav. ogne.] 1. Pertaining to, having the nature of, fire; containing fire; resembling fire; as, an igneous appearance.
2. (Geol.) Resulting from, or produced by, the action of fire; as, lavas and basalt are igneous rocks.