cayman vs caiman

cayman and caiman both are nouns.

Word	Noun	Adjective	Verb	Adverb
cayman	Yes	No	No	No
caiman	Yes	No	No	No

As nouns, cayman and caiman are synonyms defined as:

cayman and caiman: a semiaquatic reptile of Central and South America that resembles an alligator but has a more heavily armored belly

cayman (noun)	caiman (noun)
a semiaquatic reptile of Central and South America that resembles an alligator but has a more heavily armored belly	a semiaquatic reptile of Central and South America that resembles an alligator but has a more heavily armored belly