equestrian sport vs riding

equestrian sport and riding both are nouns.

Word	Noun	Adjective	Verb	Adverb
equestrian sport	Yes	No	No	No
riding	Yes	No	No	No

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

equestrian sport: a sport that tests horsemanship
riding: the sport of sitting on the back of a horse while controlling its movements

Other hypernyms of equestrian sport include equitation, horseback riding.

equestrian sport (noun)	riding (noun)
a sport that tests horsemanship	travel by being carried on horseback
	the sport of sitting on the back of a horse while controlling its movements