dirt track vs racecourse

dirt track and racecourse both are nouns.

Word	Noun	Adjective	Verb	Adverb
dirt track	Yes	No	No	No
racecourse	Yes	No	No	No

As nouns, racecourse is a hypernym of dirt track; that is, racecourse is a word with a broader meaning than dirt track:

Other hypernyms of dirt track include racetrack, raceway, track.

dirt track (noun)	racecourse (noun)
a racetrack that is not paved	a course over which races are run