The Collaborative International Dictionary of English v.0.48:

Coop \Coop\ (k[=oo]p), n. [Cf. AS. cypa a measure, D. kuip tub,
   Icel. kupa bowl, G. kufe coop tub; all fr. L. cupa vat, tub,
   LL. cupa, copa, cup. See Cup, and cf. Keeve.]
   [1913 Webster]
   1. A barrel or cask for liquor. [Obs.] --Johnson.
      [1913 Webster]

   2. An inclosure for keeping small animals; a pen; especially,
      a grated box for confining poultry.
      [1913 Webster]

   3. A cart made close with boards; a tumbrel. [Scotch]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coop \Coop\, v. t. [imp. & p. p. Cooped; p. pr. & vb. n.
   Cooping.]
   To confine in a coop; hence, to shut up or confine in a
   narrow compass; to cramp; -- usually followed by up,
   sometimes by in.
   [1913 Webster]

         The Trojans cooped within their walls so long.
                                                  --Dryden.
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         The contempt of all other knowledge . . . coops the
         understanding up within narrow bounds.   --Locke.
   [1913 Webster]

   2. To work upon in the manner of a cooper. [Obs.] "Shaken
      tubs . . . be new cooped." --Holland.

   Syn: To crowd; confine; imprison.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

co-op \co"-op\ (k[=o]"[o^]p), n. [ contraction of co-operative
   enterprise.]
   a commercial enterprise run for the benefit of its owners.

   Syn: cooperative, coop.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

coop
    n 1: a farm building for housing poultry [syn: chicken coop,
         coop, hencoop, henhouse]
    2: an enclosure made or wire or metal bars in which birds or
       animals can be kept [syn: cage, coop]