Source : Webster's Revised Unabridged Dictionary (1913)

Peat \Peat\, n. [Prob. for beat, prop., material used to make
   the fire burn better, fr. AS. b?tan to better, mend (a fire),
   b?t advantage. See {Better}, {Boot} advantage.]
   A substance of vegetable origin, consisting of roots and
   fibers, moss, etc., in various stages of decomposition, and
   found, as a kind of turf or bog, usually in low situations,
   where it is always more or less saturated with water. It is
   often dried and used for fuel.

   {Peat bog}, a bog containing peat; also, peat as it occurs in
      such places; peat moss.

   {Peat moss}.
   (a) The plants which, when decomposed, become peat.
   (b) A fen producing peat.
   (c) (Bot.) Moss of the genus {Sphagnum}, which often grows
       abundantly in boggy or peaty places.

   {Peat reek}, the reek or smoke of peat; hence, also, the
      peculiar flavor given to whisky by being distilled with
      peat as fuel. [Scot.]