The Collaborative International Dictionary of English v.0.48:

bounds \bounds\ n.
   1. the line or plane indicating the limit or extent of
      something; as, the fotball was caught out of bounds.

   Syn: boundary, bound.
        [WordNet 1.5]

   2. the greatest possible extent or degree of something.

   Syn: limit, boundary.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

bounds
    n 1: the line or plane indicating the limit or extent of
         something [syn: boundary, bound, bounds]