From The Collaborative International Dictionary of English v.0.48 :
Cebidae \Cebidae\ prop. n. A natural family including all the New World monkeys except marmosets and tamarins. Syn: family Cebidae. [WordNet 1.5]From WordNet (r) 3.0 (2006) :
Cebidae n 1: all the New World monkeys except marmosets and tamarins [syn: Cebidae, family Cebidae]