What term refers to a depression or cavity in a bone?

The correct term that refers to a depression or cavity in a bone is "fossa." In anatomical terminology, a fossa is a shallow depression or hollow that can be found in various bones. It is important in the context of bone structure and function, as it often serves as a site where muscles, tendons, or ligaments attach or where other bones articulate.

The term "foramen" typically refers to an opening or hole in a bone that allows for the passage of nerves and blood vessels, thus it does not describe a depression or cavity. "Process" refers to a projection or outgrowth from a bone where muscles or connective tissues may attach. "Sinus" denotes a cavity within a bone that is usually filled with air and sometimes serves to lighten the skull or play a role in resonating sound. While both sinuses and fossae can be cavities within bones, a fossa specifically describes the type of depression sought in this question.