Crupper /(kr?p"p?r in U.S.; kr?p"?r in Eng.)/

Crup·per

Crupper

n.
  1. The buttocks or rump of a horse.
  2. A leather loop, passing under a horse's tail, and buckled to the saddle to keep it from slipping forwards.

Crupper

v. t.
  1. To fit with a crupper; to place a crupper upon; as, to crupper a horse.