cuticle

Etymology

From Middle French cuticule, from Latin cuticula (“cuticle, skin”).

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. 1992, Toni Morrison, Jazz, Vintage (2016), page 38
3. Dead or cornified epidermis.
4. (zoology, botany) A noncellular protective covering outside the epidermis of many invertebrates and plants.
5. A thin skin formed on the surface of a liquid.