cuticle

noun

1. The outermost layer of the skin of vertebrates; the epidermis.
2. The strip of hardened skin at the base and sides of a fingernail or toenail.

   “By that time she has pushed back his cuticles, cleaned his nails and painted them with clear polish.”

3. Dead or cornified epidermis.
4. A noncellular protective covering outside the epidermis of many invertebrates and plants.
5. A thin skin formed on the surface of a liquid.
6. A protective layer on the shell of a bird's egg.