Crupper
Crupper (kr?p"p?r in U.S.; kr?p"?r in Eng.) , noun
[French croupi{not transcribed}re, from croupe. See Croup the rump of a horse.]
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 , transitive verb
To fit with a crupper; to place a crupper upon; as, to crupper a horse.