Source : Webster's Revised Unabridged Dictionary (1913)

Pyrogenous \Py*rog"e*nous\, a. [Gr. ? fire + genous: cf. F.
   purog[`e]ne, Gr. ?.]
   Produced by fire; igneous. --Mantell. .

Source : WordNet®

pyrogenous
     adj 1: produced by or producing fever [syn: {pyrogenic}, {pyrogenetic}]
     2: 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" [syn: {igneous}, {pyrogenic}]