1. (adj)igneous, pyrogenic, pyrogenous produced under conditions involving intense heat "igneous rock is rock formed by solidification from a molten state; especially from molten magma"; "igneous fusion is fusion by heat alone"; "pyrogenic strata"
2. (adj)igneous, eruptive produced by the action of fire or intense heat "rocks formed by igneous agents"
3. (adj)fiery, igneous like or suggestive of fire "a fiery desert wind"; "an igneous desert atmosphere"