invalidate

/ɪnˈvælɪdeɪt/
verb
  1. To make something no longer legally or officially acceptable.
    • A missing signature will invalidate the entire document.
    • If you break the seal, it invalidates the warranty.
    • The court's decision invalidated the old law.
  2. To prove that something is false or incorrect.
    • His alibi was invalidated by the security camera footage.
    • The experiment invalidated the hypothesis that sugar causes hyperactivity.
    • New evidence invalidated the earlier theory.