keratinization

/ˌkɛrətɪnɪˈzeɪʃən/
noun
  1. The process by which cells in the skin, hair, and nails fill with keratin and become hard and waterproof.
    • The doctor explained that normal keratinization keeps the skin healthy.
    • Some skin disorders involve abnormal keratinization, causing rough patches.
    • Keratinization helps protect the body from germs and moisture loss.