Olympics vs athletics

Olympics and athletics both are nouns.

Word	Noun	Adjective	Verb	Adverb
Olympics	Yes	No	No	No
athletics	Yes	No	No	No

As nouns, athletics is a hypernym of Olympics; that is, athletics is a word with a broader meaning than Olympics:

Olympics: the modern revival of the ancient games held once every 4 years in a selected country
athletics: a contest between athletes

Other hypernyms of Olympics include athletic competition, athletic contest.

Olympics (noun)	athletics (noun)
the modern revival of the ancient games held once every 4 years in a selected country	an active diversion requiring physical exertion and competition
	participation in sports events as an extracurricular activity
	a contest between athletes