butter bean vs lima bean

butter bean and lima bean both are nouns.

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

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

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

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

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