The Collaborative International Dictionary of English v.0.48:

nonhuman \nonhuman\ adj.
   not human. Opposite of human. [Narrower terms: anthropoid,
   anthropoidal, apelike; bloodless; dehumanized, unhuman;
   grotesque, monstrous, unnatural; mechanical]
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

nonhuman
    adj 1: not human; not belonging to or produced by or appropriate
           to human beings; "nonhuman primates such as chimpanzees"
           [ant: human]