refine

/rɪˈfaɪn/
verb
  1. To remove impurities or unwanted elements from a substance, making it purer.
    • Gold must be refined to remove other metals.
    • The factory refines crude oil into gasoline.
    • They refine sugar to make it white and granular.
  2. To improve something by making small changes, making it more precise or effective.
    • The chef refined the recipe to make it even tastier.
    • He refined his drawing skills through years of practice.
    • She refined her speech after getting feedback from friends.