rosebush vs sweetbrier

rosebush and sweetbrier both are nouns.

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

As nouns, sweetbrier is a hyponym of rosebush; that is, sweetbrier is a word with a more specific, narrower meaning than rosebush:

rosebush: any of many shrubs of the genus Rosa that bear roses
sweetbrier: Eurasian rose with prickly stems and fragrant leaves and bright pink flowers followed by scarlet hips

rosebush (noun)	sweetbrier (noun)
any of many shrubs of the genus Rosa that bear roses	Eurasian rose with prickly stems and fragrant leaves and bright pink flowers followed by scarlet hips