minor league vs bush league

minor league and bush league both are nouns.

Word	Noun	Adjective	Verb	Adverb
minor league	Yes	No	No	No
bush league	Yes	No	No	No

As nouns, minor league and bush league are synonyms defined as:

minor league and bush league: a league of teams that do not belong to a major league (especially baseball)

Other synonyms of minor league include minors.

minor league (noun)	bush league (noun)
a league of teams that do not belong to a major league (especially baseball)	a league of teams that do not belong to a major league (especially baseball)