crupper

This term is highly specialized and belongs to the register of equestrian equipment and tack. It is rarely encountered outside of professional horse riding, livestock management, or historical texts concerning cavalry and carriage driving. Because it describes a specific piece of hardware, it is used in a literal, technical sense rather than a metaphorical one.

In practical usage, the word is often associated with steep terrain or high-energy activities where the risk of a saddle sliding forward is increased. It is distinct from the breastplate, which prevents the saddle from slipping backward; together, these pieces of tack stabilize the saddle on the horse's back.