polo neck

/ˈpoʊloʊˌnɛk/
noun
  1. A type of sweater or shirt with a high, close-fitting collar that folds over.
    • He bought a cashmere polo-neck for the cold weather.
    • The actor looked elegant in a cream polo-neck and blazer.
    • She wore a black polo-neck under her winter coat.
Synonyms