crupperPronunciation: /ˈkrʌpə/Definition of crupper noun a strap buckled to the back of a saddle and looped under the horse’s tail to prevent the saddle or harness from slipping forward. Origin: Middle English: from Old French cropiere, related to croupe (see croup2). Compare with croupiercrupper in other Oxford dictionaries Definition of crupper in the US English dictionary
