sports jacket vs sport jacket

sports jacket and sport jacket both are nouns.

Word	Noun	Adjective	Verb	Adverb
sports jacket	Yes	No	No	No
sport jacket	Yes	No	No	No

As nouns, sports jacket and sport jacket are synonyms defined as:

sports jacket and sport jacket: lightweight single-breasted jacket; often striped in the colors of a club or school

Other synonyms of sports jacket include blazer, sport coat, sports coat.

sports jacket (noun)	sport jacket (noun)
lightweight single-breasted jacket; often striped in the colors of a club or school	lightweight single-breasted jacket; often striped in the colors of a club or school