rosebush vs bush

rosebush and bush both are nouns.

Word	Noun	Adjective	Verb	Adverb
rosebush	Yes	No	No	No
bush	Yes	Yes	Yes	No

As nouns, bush is a hypernym of rosebush; that is, bush is a word with a broader meaning than rosebush:

Other hypernyms of rosebush include shrub.

rosebush (noun)	bush (noun)
any of many shrubs of the genus Rosa that bear roses	hair growing in the pubic area
	dense vegetation consisting of stunted trees or bushes
	a large wilderness area
	a low woody perennial plant usually having several major stems

rosebush (adjective)	bush (adjective)
	not of the highest quality or sophistication

rosebush (verb)	bush (verb)
	provide with a bushing