track star vs genius

track star and genius both are nouns.

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

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

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

track star (noun)	genius (noun)
a star runner	exceptional creative ability
	a natural talent
	unusual mental ability
	someone who has exceptional intellectual ability and originality
	someone who is dazzlingly skilled in any field