Corneum

Part of speech: noun

Definitions

1. A protective outer layer of skin or tissue, typically referring to the stratum corneum in the epidermis
2. It serves as a barrier to prevent moisture loss and protect against environmental damage
3. This layer consists of dead cells that provide a durable and resilient surface, essential for skin health and function

Etymology: "Corneum" is the Latin neuter form of "corneus", meaning "horny" or "made of horn," derived from "cornu" (horn). The word was borrowed into English as a technical term, and in anatomy it names the stratum corneum, the outermost layer of the epidermis. The name describes the tissue's hard, horn-like, keratinised texture: the cells at this layer are dead and flattened, packed with keratin, the same tough protein that makes up animal horn and hair. The Latin root "cornu" is the same word that gives English "cornea," the transparent covering of the eye, and "unicorn," a creature named for its single horn. The pairing shows how a plain physical comparison, horn-like hardness, was reused across anatomy and myth.

Synonyms: horny layer, stratum corneum