Source : Webster's Revised Unabridged Dictionary (1913)

Antipyretic \An`ti*py*ret"ic\, a. (Med.)
   Efficacious in preventing or allaying fever. -- n. A
   febrifuge.

Source : WordNet®

antipyretic
     adj : preventing or alleviating fever [ant: {pyretic}]
     n : any medicine that lowers body temperature to prevent or
         alleviate fever [syn: {febrifuge}]