bunny rabbit vs bunny

bunny rabbit and bunny both are nouns.

Word	Noun	Adjective	Verb	Adverb
bunny rabbit	Yes	No	No	No
bunny	Yes	No	No	No

As nouns, bunny rabbit and bunny are synonyms defined as:

bunny rabbit (noun)	bunny (noun)
(usually informal) especially a young rabbit	(usually informal) especially a young rabbit
	a young waitress in a nightclub whose costume includes the tail and ears of a rabbit