red-bellied terrapin vs redbelly

red-bellied terrapin and redbelly both are nouns.

Word	Noun	Adjective	Verb	Adverb
red-bellied terrapin	Yes	No	No	No
redbelly	Yes	No	No	No

As nouns, red-bellied terrapin and redbelly are synonyms defined as:

red-bellied terrapin and redbelly: freshwater turtle of Chesapeake Bay tributaries having red markings on the lower shell

Other synonyms of red-bellied terrapin include Pseudemys rubriventris, red-bellied turtle.

red-bellied terrapin (noun)	redbelly (noun)
freshwater turtle of Chesapeake Bay tributaries having red markings on the lower shell	freshwater turtle of Chesapeake Bay tributaries having red markings on the lower shell