champion vs advocate

champion and advocate both are nouns.

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

As nouns, advocate is a hypernym of champion; that is, advocate is a word with a broader meaning than champion:

Other hypernyms of champion include advocator, exponent, proponent.

champion (noun)	advocate (noun)
someone who fights for a cause	a person who pleads for a cause or propounds an idea
someone who has won first place in a competition	a lawyer who pleads cases in court
a person who backs a politician or a team etc.
someone who is dazzlingly skilled in any field

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

champion (verb)	advocate (verb)
protect or fight for as a champion	push for something
	speak, plead, or argue in favor of