plunk for vs champion

plunk for is not a noun while champion is a noun.

Word	Noun	Adjective	Verb	Adverb
plunk for	No	No	Yes	No
champion	Yes	Yes	Yes	No

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

Other hyponyms of plunk for include guarantee, warrant, defend.

plunk for (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

plunk for (adjective)	champion (adjective)
	holding first place in a contest

plunk for (verb)	champion (verb)
be behind; approve of	protect or fight for as a champion