lima bean vs butter bean

lima bean and butter bean both are nouns.

Word	Noun	Adjective	Verb	Adverb
lima bean	Yes	No	No	No
butter bean	Yes	No	No	No

As nouns, lima bean and butter bean are synonyms defined as:

lima bean and butter bean: bush bean plant cultivated especially in southern United States having small flat edible seeds

Other synonyms of lima bean include butter-bean plant, Phaseolus lunatus, sieva bean.

lima bean (noun)	butter bean (noun)
broad flat beans simmered gently; never eaten raw	small flat green bean similar to lima beans
bush or tall-growing bean plant having large flat edible seeds	bush bean plant cultivated especially in southern United States having small flat edible seeds
bush bean plant cultivated especially in southern United States having small flat edible seeds