crocodile

noun

1. any of a subfamily (Crocodylinae) of large, flesh-eating, lizardlike crocodilian reptiles living in or around tropical streams and having thick, horny skin composed of scales and plates, a long tail, and a long, narrow, triangular head with massive jaws: it has on each side of the lower jaw a large tooth that protrudes upward from its closed mouth
2. leather made from a crocodile's hide
3. Brit. a long line of persons, esp. school children, moving in file, as when out for a walk