endorse vs champion

endorse is not a noun while champion is a noun.

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

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

Other hyponyms of endorse include guarantee, warrant, defend.

endorse (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

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

endorse (verb)	champion (verb)
sign as evidence of legal transfer	protect or fight for as a champion
be behind; approve of
guarantee as meeting a certain standard
give support or one's approval to