Either of two large semiaquatic reptiles, Alligator mississipiensis of the southeast United States or A. sinensis of China, having sharp teeth and powerful jaws. They differ from crocodiles in having a alligator definition francais, shorter snout. A large, meat-eating, aquatic reptile having sharp teeth and powerful jaws. Alligators have a broader, shorter snout than crocodiles, and their teeth do not show when the jaws are closed.
The two living species are the American alligator ( A. mississippiensis) and the Chinese alligator ( A. sinensis). In addition, several extinct species of alligator are known from fossil remains.