The Collaborative International Dictionary of English v.0.48:

Cotswold \Cots"wold`\ (k?ts"w?ld`), n. [Cot a cottage or hut +
   wold an open country.]
   An open country abounding in sheepcotes, as in the Cotswold
   hills, in Gloucestershire, England.
   [1913 Webster]

   Cotswold sheep, a long-wooled breed of sheep, formerly
      common in the counties of Gloucester, Hereford, and
      Worcester, Eng.; -- so called from the Cotswold Hills. The
      breed is now chiefly amalgamated with others.
      [1913 Webster]