equestrian vs buster

equestrian and buster both are nouns.

Word	Noun	Adjective	Verb	Adverb
equestrian	Yes	Yes	No	No
buster	Yes	No	No	No

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

equestrian (noun)	buster (noun)
a person skilled in equitation	a person (or thing) that breaks up or overpowers something
	a person who breaks horses
	a robust child
	an informal form of address for a man
	a person born in the generation following the baby boom when the birth rate fell dramatically

equestrian (adjective)	buster (adjective)
of or relating to or featuring horseback riding
of or relating to or composed of knights