permanent

adjective
  1. Lasting or intended to last or remain unchanged indefinitely. adjective
    The ink left a permanent mark on the paper.
    They are looking for a permanent solution to the problem.
  2. A chemical hair treatment that makes hair curly or wavy for an extended period. noun
    She decided to get a permanent to change her straight hair to curls.
    The salon offers various types of permanents for different hair textures.