The Collaborative International Dictionary of English v.0.48:

moorfowl \moorfowl\, moor fowl \moor fowl\n. (Zool.)
   1. A reddish-brown grouse (Lagopus Scoticus) of upland
      moors of Great Britain; the European ptarmigan, or red
      grouse, also called the moorgame.

   Syn: red grouse, moorbird, moorgame, Lagopus scoticus.
        [WordNet 1.5]

   2. The European heath grouse. See under Heath.
      [1913 Webster]

WordNet (r) 3.0 (2006):

red grouse
    n 1: reddish-brown grouse of upland moors of Great Britain [syn:
         red grouse, moorfowl, moorbird, moor-bird,
         moorgame, Lagopus scoticus]