crupper /krupˈər/

1. A strap of leather fastened to the saddle and passing under the horse's tail to keep the saddle in its place
2. The hind part of a horse

• lose one's bearings
• lose one's cool
• lose oneself
• lose one's hair
• lose one's head
• lose one's heart to
• lose one's marbles
• lose one's nerve
• lose one's place
• lose one's rag
• lose one's seat
• lose one's shirt
• lose one's tongue
• lose out
• loser
• losers
• loses
• lose sight of
• lose the exchange
• lose the place
• lose the plot
• lose time
• lose track of
• lose way
• lose weight