Source : Webster's Revised Unabridged Dictionary (1913)

Prostatitis \Pros`ta*ti"tis\, n. [NL. See {Prostate}, and
   {-itis}.] (Med.)
   Inflammation of the prostate.

Source : WordNet®

prostatitis
     n : inflammation of the prostate gland characterized by perineal
         pain and irregular urination and (if severe) chills and
         fever