football player vs jock

football player and jock both are nouns.

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

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

Other hypernyms of football player include athlete, participant, player.

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