in ‧ val ‧ i ‧ date AC /ɪnˈvælədeɪt, ɪnˈvælɪdeɪt/ BrE AmE verb [transitive]
[ Word Family: verb : ↑ validate ≠ ↑ invalidate ; noun : ↑ validity ≠ ↑ invalidity ; adjective : ↑ valid ≠ ↑ invalid ]
1 . to make a document, ticket, claim etc no longer legally or officially acceptable:
Failure to disclose all relevant changes may invalidate your policy.
2 . to show that something such as a belief or explanation is wrong:
Later findings invalidated the theory.