prize winner vs winner

prize winner and winner both are nouns.

Word	Noun	Adjective	Verb	Adverb
prize winner	Yes	No	No	No
winner	Yes	No	No	No

As nouns, winner is a hypernym of prize winner; that is, winner is a word with a broader meaning than prize winner:

prize winner (noun)	winner (noun)
the winner of a lottery	the contestant who wins the contest
	a gambler who wins a bet
	a person with a record of successes