hockey player vs jock

hockey player and jock both are nouns.

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

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

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

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