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}.

Potassium \Po*tas"si*um\, n. [NL. See {Potassa}, {Potash}.]
   (Chem.)
   An Alkali element, occurring abundantly but always combined,
   as in the chloride, sulphate, carbonate, or silicate, in the
   minerals sylvite, kainite, orthoclase, muscovite, etc. Atomic
   weight 39.0. Symbol K (Kalium).

   Note: It is reduced from the carbonate as a soft white metal,
         lighter than water, which oxidizes with the greatest
         readiness, and, to be preserved, must be kept under
         liquid hydrocarbons, as naphtha or kerosene. Its
         compounds are very important, being used in glass
         making, soap making, in fertilizers, and in many drugs
         and chemicals.

   {Potassium permanganate}, the salt {KMnO4}, crystallizing in
      dark red prisms having a greenish surface color, and
      dissolving in water with a beautiful purple red color; --
      used as an oxidizer and disinfectant. The name {chameleon
      mineral} is applied to this salt and also to potassium
      manganate.

   {Potassium bitartrate}. See {Cream of tartar}, under {Cream}.

Source : WordNet®

potassium permanganate
     n : a poisonous salt that forms dark purple crystals and is
         purple-red when dissolved in water; used as an oxidizing
         and bleaching agent and as a disinfectant and antiseptic
         [syn: {permanganate of potash}]