luau vs feast

luau and feast both are nouns.

Word	Noun	Adjective	Verb	Adverb
luau	Yes	No	No	No
feast	Yes	No	Yes	No

As nouns, feast is a hypernym of luau; that is, feast is a word with a broader meaning than luau:

luau: an elaborate Hawaiian feast or party (especially one accompanied by traditional foods and entertainment)
feast: an elaborate party (often outdoors)

Other hypernyms of luau include fete, fiesta.

luau (noun)	feast (noun)
an elaborate Hawaiian feast or party (especially one accompanied by traditional foods and entertainment)	something experienced with great delight
	an elaborate party (often outdoors)
	a meal that is well prepared and greatly enjoyed
	a ceremonial dinner party for many people

luau (verb)	feast (verb)
	partake in a feast or banquet
	provide a feast or banquet for
	gratify