fiesta vs party

fiesta and party both are nouns.

Word	Noun	Adjective	Verb	Adverb
fiesta	Yes	No	No	No
party	Yes	No	Yes	No

As nouns, party is a hypernym of fiesta; that is, party is a word with a broader meaning than fiesta:

fiesta: an elaborate party (often outdoors)
party: an occasion on which people can assemble for social interaction and entertainment

fiesta (noun)	party (noun)
an elaborate party (often outdoors)	an occasion on which people can assemble for social interaction and entertainment
	a gathering of people for pleasure
	an organization to gain political power
	a band of people associated temporarily in some activity
	a person involved in legal proceedings

fiesta (verb)	party (verb)
	have or participate in a party