The Collaborative International Dictionary of English v.0.48:

Chopping \Chop"ping\, n.
   Act of cutting by strokes.
   [1913 Webster]

   Chopping block, a solid block of wood on which butchers and
      others chop meat, etc.

   Chopping knife, a knife for chopping or mincing meat,
      vegetables, etc.; -- usually with a handle at the back of
      the blade instead of at the end.
      [1913 Webster]

WordNet (r) 3.0 (2006):

chopping block
    n 1: a steady wooden block on which food can be cut or diced or
         wood can be split