The Collaborative International Dictionary of English v.0.48:

game show \game" show`\ (g[=a]m"sh[=o]`), n.
   a television program in which contestants compete for awards.
   The contestants are members of the public selected to
   participate on the show, and not employed by the producer of
   the show.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

game show
    n 1: a television or radio program in which contestants compete
         for awards [syn: game show, giveaway]