(adj) produced under conditions involving intense heat, Syn. pyrogenous, pyrogenic, Example:igneous rock is rock formed by solidification from a molten state; especially from molten magma; igneous fusion is fusion by heat alone; pyrogenic strata
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
a. [ Pyro- + -gen + -ic. ] (Physiol.) Producing heat; -- said of substances, as septic poisons, which elevate the temperature of the body and cause fever. [ 1913 Webster ]