polo-neck vs tee shirt

polo-neck and tee shirt both are nouns.

Word	Noun	Adjective	Verb	Adverb
polo-neck	Yes	No	No	No
tee shirt	Yes	No	No	No

As nouns, tee shirt is a hypernym of polo-neck; that is, tee shirt is a word with a broader meaning than polo-neck:

Other hypernyms of polo-neck include jersey, T-shirt, jumper, sweater.

polo-neck (noun)	tee shirt (noun)
a sweater or jersey with a high close-fitting collar	a close-fitting pullover shirt