Source : Webster's Revised Unabridged Dictionary (1913)

Pyretic \Py*ret"ic\, a. [Gr. ? burning heat, fever, from ? fire:
   cf. F. pyr['e]tique.] (Med.)
   Of or pertaining to fever; febrile.

Source : WordNet®

pyretic
     adj : causing fever [ant: {antipyretic}]