noun a strap that passes under the tail of a horse and is fastened to the saddle to prevent it from slipping forward
A crupper is a strap that runs from the back of a saddle and loops under the horse's tail to prevent the saddle from sliding forward.
In animal husbandry, a crupper may be used as part of a harness for working animals like horses or oxen.
In leatherworking, a crupper is a piece of leather used for various purposes such as harnesses or saddlery.
In a literary context, a crupper may be used as a metaphor for something that holds back or restrains progress or development in a story or character.
A psychologist may use the term crupper to refer to psychological barriers or obstacles that prevent a person from moving forward or making progress in therapy.