The Collaborative International Dictionary of English v.0.48:

Cropper \Crop"per\ (kr?p"p?r), n.
   1. One that crops.
      [1913 Webster]

   2. A variety of pigeon with a large crop; a pouter.
      [1913 Webster]

   3. (Mech.) A machine for cropping, as for shearing off bolts
      or rod iron, or for facing cloth.
      [1913 Webster]

   4. A fall on one's head when riding at full speed, as in
      hunting; hence, a sudden failure or collapse. [Slang.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

cropper
    n 1: small farmers and tenants [syn: sharecropper, cropper,
         sharecrop farmer]