prizewinning vs champion

prizewinning is not a noun while champion is a noun.

Word	Noun	Adjective	Verb	Adverb
prizewinning	No	Yes	No	No
champion	Yes	Yes	Yes	No

As adjectives, prizewinning and champion are synonyms defined as:

prizewinning (noun)	champion (noun)
	someone who fights for a cause
	someone who has won first place in a competition
	a person who backs a politician or a team etc.
	someone who is dazzlingly skilled in any field

prizewinning (adjective)	champion (adjective)
holding first place in a contest	holding first place in a contest

prizewinning (verb)	champion (verb)
	protect or fight for as a champion