The Collaborative International Dictionary of English v.0.48:

Cornish \Cor"nish\ (k?r"n?sh), a.
   Of or pertaining to Cornwall, in England.
   [1913 Webster]

   Cornish chough. See Chough.

   Cornish engine, a single-acting pumping engine, used in
      mines, in Cornwall and elsewhere, and for water works. A
      heavy pump rod or plunger, raised by the steam, forces up
      the water by its weight, in descending.
      [1913 Webster]