Trooper

Troop·er

Trooper

n.
  1. A soldier in a body of cavalry; a cavalryman; also, the horse of a cavalryman.
  2. A state police officer; -- also called state trooper. [U. S.]
  3. A mounted policeman. [Australia]
  4. Trouper.

Phrases & Compounds
like a trooper
with energy, endurance, or enthusiasm; as, to work like a trooper.