track star vs champion

track star and champion both are nouns.

Word	Noun	Adjective	Verb	Adverb
track star	Yes	No	No	No
champion	Yes	Yes	Yes	No

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

Other hypernyms of track star include ace, adept, genius, hotshot, maven, mavin, sensation, star, superstar, virtuoso, whiz, whizz, wiz, wizard.

track star (noun)	champion (noun)
a star runner	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

track star (adjective)	champion (adjective)
	holding first place in a contest

track star (verb)	champion (verb)
	protect or fight for as a champion