field sport vs athletics

field sport and athletics both are nouns.

Word	Noun	Adjective	Verb	Adverb
field sport	Yes	No	No	No
athletics	Yes	No	No	No

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

Other hypernyms of field sport include sport.

field sport (noun)	athletics (noun)
a sport that is played outdoors	an active diversion requiring physical exertion and competition
	participation in sports events as an extracurricular activity
	a contest between athletes