Search Result for "dimetrodon": 
Wordnet 3.0

NOUN (1)

1. carnivorous dinosaur of the Permian in North America having a crest or dorsal sail; 



WordNet (r) 3.0 (2006):

dimetrodon
    n 1: carnivorous dinosaur of the Permian in North America having
         a crest or dorsal sail