contender vs champion

contender and champion both are nouns.

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

As nouns, champion is a hyponym of contender; that is, champion is a word with a more specific, narrower meaning than contender:

contender (noun)	champion (noun)
the contestant you hope to defeat	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

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

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