Princeton's WordNet

1. Neandertal man, Neanderthal man, Neandertal, Neanderthal, Homo sapiens neanderthalensis(adj)

   extinct robust human of Middle Paleolithic in Europe and western Asia

2. Neanderthal, Neanderthalian, Neandertal(adj)

   relating to or belonging to or resembling Neanderthal man

   "Neanderthal skull"

3. boorish, loutish, neanderthal, neandertal, oafish, swinish(adj)

   ill-mannered and coarse and contemptible in behavior or appearance

   "was boorish and insensitive"; "the loutish manners of a bully"; "her stupid oafish husband"; "aristocratic contempt for the swinish multitude"