red-bellied turtle vs redbelly

red-bellied turtle and redbelly both are nouns.

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

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

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

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

red-bellied turtle (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