igneous (Adjective) — Produced under conditions involving intense heat. ex. "igneous rock is rock formed by solidification from a molten state; especially from molten magma"
igneous (Adjective) — (geology) produced by the action of fire or intense heat. ex. "rocks formed by igneous agents"
igneous (Adjective) — Like or suggestive of fire. ex. "an igneous desert atmosphere"