breaking ball vs curve ball

breaking ball and curve ball both are nouns.

Word	Noun	Adjective	Verb	Adverb
breaking ball	Yes	No	No	No
curve ball	Yes	No	No	No

As nouns, breaking ball and curve ball are synonyms defined as:

breaking ball and curve ball: a pitch of a baseball that is thrown with spin so that its path curves as it approaches the batter

Other synonyms of breaking ball include bender, curve.

breaking ball (noun)	curve ball (noun)
a pitch of a baseball that is thrown with spin so that its path curves as it approaches the batter	a pitch of a baseball that is thrown with spin so that its path curves as it approaches the batter