sheepdog

/SH IY1 P D AO0 G/
noun
  1. 1

    A breed of dog, used for herding sheep.

  2. 2

    A breed of dog used for guarding sheep.

  3. 3

    A chaperon; an adult who accompanies other people in a supervisory role.

  4. 4

    (police) A police officer.

verb
  1. 1

    To chaperon or shepherd.

Source: https://en.wiktionary.org/wiki/sheepdog