footballer vs jock

footballer and jock both are nouns.

Word	Noun	Adjective	Verb	Adverb
footballer	Yes	No	No	No
jock	Yes	No	No	No

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

Other hypernyms of footballer include athlete, participant, player.

footballer (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