sport shirt vs polo shirt

sport shirt and polo shirt both are nouns.

Word	Noun	Adjective	Verb	Adverb
sport shirt	Yes	No	No	No
polo shirt	Yes	No	No	No

As nouns, sport shirt and polo shirt are synonyms defined as:

sport shirt and polo shirt: a shirt with short sleeves designed for comfort and casual wear

sport shirt (noun)	polo shirt (noun)
a shirt with short sleeves designed for comfort and casual wear	a shirt with short sleeves designed for comfort and casual wear