basketball player vs jock

basketball player and jock both are nouns.

Word	Noun	Adjective	Verb	Adverb
basketball player	Yes	No	No	No
jock	Yes	No	No	No

As nouns, jock is a hypernym of basketball player; that is, jock is a word with a broader meaning than basketball player:

Other hypernyms of basketball player include athlete.

basketball player (noun)	jock (noun)
an athlete who plays basketball	a support for the genitals worn by men engaging in strenuous exercise
	a person trained to compete in sports