polo-neck vs jersey

polo-neck and jersey both are nouns.

Word	Noun	Adjective	Verb	Adverb
polo-neck	Yes	No	No	No
jersey	Yes	No	No	No

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

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

polo-neck (noun)	jersey (noun)
a sweater or jersey with a high close-fitting collar	a slightly elastic machine-knit fabric
	a close-fitting pullover shirt