Source : Webster's Revised Unabridged Dictionary (1913)

Ceratosaurus \Cer`a*to*sau"rus\, n. [NL., fr. Gr. ke`ras a horn
   + ? lizard.] (Paleon.)
   A carnivorous American Jurassic dinosaur allied to the
   European Megalosaurus. The animal was nearly twenty feet in
   length, and the skull bears a bony horn core on the united
   nasal bones. See Illustration in Appendix.

Source : WordNet®

ceratosaurus
     n : primitive medium-sized theropod; swift-running bipedal
         carnivorous dinosaur having grasping hands with sharp
         claws and a short horn between the nostrils; Jurassic in
         North America [syn: {ceratosaur}]