From The Collaborative International Dictionary of English v.0.48 :
clit \clit\ n.
Same as clitoris. [Vulgar slang]
Syn: clitoris, button.
[WordNet 1.5]
From WordNet (r) 3.0 (2006) :
clit
n 1: a female sexual organ homologous to the penis [syn:
clitoris, clit, button]