| a. | 1. | Pertaining to, having the nature of, fire; containing fire; resembling fire; |
| 2. | (Geol.) Resulting from, or produced by, the action of fire; |
| Adj. | 1. | igneous - 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" Synonyms: pyrogenic, pyrogenous |
| 2. | igneous - like or suggestive of fire; "the burning sand"; "a fiery desert wind"; "an igneous desert atmosphere" Synonyms: fiery |