Which term is used to describe an appendage of the skin?

The term that describes an appendage of the skin is "nail." Nails are composed of keratin, a tough protein, and serve several important functions, including protecting the tips of fingers and toes, enhancing the sense of touch by providing support to digital pads, and assisting in grasping objects.

While the scalp refers to the skin on the head that supports hair growth, it is not considered an appendage. "Cutaneous" relates to the skin itself rather than a specific structure that extends from it. The dermis is the layer beneath the epidermis and contains important components such as blood vessels, nerves, and hair follicles, but it is not an appendage on its own. Thus, nails are correctly identified as an appendage of the skin, as they are specialized structures that grow from the epidermis and perform specific functions.