butter-flower vs kingcup

butter-flower and kingcup both are nouns.

Word	Noun	Adjective	Verb	Adverb
butter-flower	Yes	No	No	No
kingcup	Yes	No	No	No

As nouns, butter-flower and kingcup are synonyms defined as:

butter-flower and kingcup: any of various plants of the genus Ranunculus

Other synonyms of butter-flower include buttercup, butterflower, crowfoot, goldcup.

butter-flower (noun)	kingcup (noun)
any of various plants of the genus Ranunculus	any of various plants of the genus Ranunculus
	swamp plant of Europe and North America having bright yellow flowers resembling buttercups