wheel horse

  1. the horse, or one of the horses, harnessed nearest the front wheels of a vehicle
  2. ☆ a person who works especially hard and steadily in any enterprise

See wheel horse in American Heritage Dictionary 4

noun
  1. The horse in a team that follows the leader and is harnessed nearest the front wheels.
  2. A diligent, dependable worker, especially in a political organization.

Learn more about wheel horse

link/cite print suggestion box