chinstraps

/CH IH1 N S T R AE0 P S/
noun
  1. 1

    A strip of leather or material used to fasten a hat or helmet under the chin.

  2. 2

    A form of beard grown under the chin.

  3. 3

    A band of colour below a bird's mouth, resembling the chinstrap of a helmet.

Source: https://en.wiktionary.org/wiki/chinstrap, https://en.wiktionary.org/wiki/chinstraps