medal winner vs medallist

medal winner and medallist both are nouns.

Word	Noun	Adjective	Verb	Adverb
medal winner	Yes	No	No	No
medallist	Yes	No	No	No

As nouns, medal winner and medallist are synonyms defined as:

medal winner and medallist: (golf) the winner at medal play of a tournament

Other synonyms of medal winner include medalist.

medal winner (noun)	medallist (noun)
(golf) the winner at medal play of a tournament	(golf) the winner at medal play of a tournament
	someone who has won a medal