Stratum corneum: The stratum corneum refers to the outermost layer of the epidermis, which is itself the outer layer of the skin.
The full name of the stratum corneum of the skin is the stratum corneum epidermidis. The other stratum corneum, the stratum corneum unguis, is the horny compact outer layer of the nail.
In Latin "stratum" = "layer" and "corneum" = "horny" so stratum corneum = horny layer.
