The Collaborative International Dictionary of English v.0.48:

Cercopithecidae \Cercopithecidae\ n.
   a natural family of Old World monkeys including the guenon,
   baboon, colobus monkey, langur, macaque, mandrill, mangabey,
   patas, and proboscis monkey.

   Syn: family Cercopithecidae.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Cercopithecidae
    n 1: Old World monkeys: guenon; baboon; colobus monkey; langur;
         macaque; mandrill; mangabey; patas; proboscis monkey [syn:
         Cercopithecidae, family Cercopithecidae]