Definitions

1. noun

a strap or band attached to the saddle and used to control the movement of a horse, especially one that is being ridden at a gallop.

“The rider used the crupper to keep the horse from bucking.”

2. noun

a strip or band, especially of metal, used to secure something, such as a sail or a rope.

“The crew used a crupper to keep the sail in place during the storm.”