cantle

This term is highly specialized and primarily used in equestrian contexts or historical armor studies. In modern English, it is rarely encountered outside of saddle-making or museums, carrying a technical register that denotes a specific structural component rather than a general shape.

When referring to saddles, the word describes a functional safety feature. In the context of armor, it refers to the protective perimeter of a piece of equipment. Because it describes a specific part of a larger object, it is used as a concrete noun in descriptive or technical prose.