Dead skin at base of nail

noun

1. An external envelope (as of an insect) secreted usually by epidermal cells
2. The outermost layer of animal integument composed of epidermis
3. A thin continuous fatty or waxy film on the external surface of many higher plants that consists chiefly of cutin
4. The outermost membranous layer of a hair consisting of overlapping scales of epithelial cells
5. Dead or horny epidermis (such as that surrounding the base and sides of a fingernail)