racetrack vs velodrome

racetrack and velodrome both are nouns.

Word	Noun	Adjective	Verb	Adverb
racetrack	Yes	No	No	No
velodrome	Yes	No	No	No

As nouns, velodrome is a hyponym of racetrack; that is, velodrome is a word with a more specific, narrower meaning than racetrack:

Other hyponyms of racetrack include cinder track, dirt track, circuit, racing circuit, speedway.

racetrack (noun)	velodrome (noun)
a course over which races are run	a banked oval track for bicycle or motorcycle racing