Definition of caimans:
(n) :
(strictly) Any of the relatively small crocodilians of the genus Caiman, within the family Alligatoridae.
(n) :
(loosely) A crocodilian of the subfamily Caimaninae, which includes the very large black caiman.
(n) :
A semi-aquatic lizard, of the genus Dracaena, found in South America. To differentiate from caimans, they are referred to as caiman lizards.
(n) :
(archaic) Alternative form of Cayman. [(archaic) Synonym of Cayman Islands: Three islands constituting an overseas territory of the United Kingdom in the Caribbean Sea.]