The Collaborative International Dictionary of English v.0.48:

Clitoris \Cli"to*ris\ (kl[imac]"t[-o]*r[i^]s or
   kl[i^]t"[-o]*r[i^]s), n. [NL., fr. Gr. kleitori`s, fr.
   klei`ein to shut up. It is concealed by the labia pudendi.]
   (Anat.)
   A small organ at the upper part of the vulva in females,
   homologous to the penis in the male.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clitoris
    n 1: a female sexual organ homologous to the penis [syn:
         clitoris, clit, button]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "clitoris":
   bag, ballocks, balls, basket, beard, breasts, cervix, cod, cods,
   cullions, family jewels, female organs, genitalia, genitals,
   gonads, labia, labia majora, labia minora, lingam, lips,
   male organs, meat, nuts, nymphae, ovary, penis, phallus,
   private parts, privates, privy parts, pubic hair, pudenda,
   reproductive organs, rocks, scrotum, secondary sex characteristic,
   sex organs, spermary, testes, testicles, uterus, vagina, vulva,
   womb, yoni