polo neck

/P OW1 L OW0 N EH0 K/
noun
  1. 1

    A high collar covering the neck; a turtleneck.

  2. 2

    A light type of shirt with such a collar; a turtleneck.

Source: https://en.wiktionary.org/wiki/polo%20neck, https://en.wiktionary.org/wiki/polo-neck