bronco buster vs buster

bronco buster and buster both are nouns.

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

As nouns, bronco buster and buster are synonyms defined as:

Other synonyms of bronco buster include broncobuster.

bronco buster (noun)	buster (noun)
a person who breaks horses	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