Source : Webster's Revised Unabridged Dictionary (1913)

Permanganate \Per*man"ga*nate\, n. (Chem.)
   A salt of permanganic acid.

   {Potassium permanganate}. (Chem.) See {Potassium
      permanganate}, under {Potassium}.

Source : WordNet®

permanganate
     n : a dark purple salt of permanganic acid; in water solution it
         is used as a disinfectant and antiseptic