immutable

/ɪˈmjutəbəl/
adjective
  1. Not changing or unable to be changed; permanent and unalterable.
    • The laws of nature are considered immutable by most scientists.
    • The company's core values are immutable, even as the market changes.
    • She accepted the immutable fact that time cannot be reversed.
What does "immutable" mean? | whatsthatwordmean | whatsthatwordmean