common bean vs bush bean

common bean and bush bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
common bean	Yes	No	No	No
bush bean	Yes	No	No	No

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

common bean: the common annual twining or bushy bean plant grown for its edible seeds or pods
bush bean: a bean plant whose bushy growth needs no supports

common bean (noun)	bush bean (noun)
any of numerous beans eaten either fresh or dried	a bean plant whose bushy growth needs no supports
the common annual twining or bushy bean plant grown for its edible seeds or pods