pentathlete vs jock

pentathlete and jock both are nouns.

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

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

Other hypernyms of pentathlete include athlete.

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