horse bean vs broad bean

horse bean and broad bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
horse bean	Yes	No	No	No
broad bean	Yes	No	No	No

As nouns, horse bean and broad bean are synonyms defined as:

horse bean and broad bean: a bean plant cultivated for use animal fodder

horse bean (noun)	broad bean (noun)
a bean plant cultivated for use animal fodder	shell beans cooked as lima beans
	a bean plant cultivated for use animal fodder
	Old World upright plant grown especially for its large flat edible seeds but also as fodder
	seed of the broad-bean plant