sport jacket vs blazer

sport jacket and blazer both are nouns.

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

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

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

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

sport jacket (noun)	blazer (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