bunny girl vs waitress

bunny girl and waitress both are nouns.

Word	Noun	Adjective	Verb	Adverb
bunny girl	Yes	No	No	No
waitress	Yes	No	Yes	No

As nouns, waitress is a hypernym of bunny girl; that is, waitress is a word with a broader meaning than bunny girl:

bunny girl: a young waitress in a nightclub whose costume includes the tail and ears of a rabbit
waitress: a woman waiter

bunny girl (noun)	waitress (noun)
a young waitress in a nightclub whose costume includes the tail and ears of a rabbit	a woman waiter

bunny girl (verb)	waitress (verb)
	serve as a waiter or waitress in a restaurant