The Collaborative International Dictionary of English v.0.48:

Cro-magnon \Cro-magnon\ prop. n.
   1. a race of human-like hominids of the Upper Paleolithic in
      Europe, considered of the same species as modern humans
      (Homo sapiens). Their skeletal remains were found mostly
      in southern France.
      [WordNet 1.5 +PJC]

   2. a member of the Cro-Magnon race.
      [PJC]

WordNet (r) 3.0 (2006):

Cro-magnon
    n 1: extinct human of Upper Paleolithic in Europe