invalid

/ɪnˈvælɪd/
adjective
  1. Not legally or officially acceptable; having no legal force.
    • The judge ruled that the evidence was invalid due to improper handling.
    • Her passport was invalid, so she could not board the plane.
    • The contract was declared invalid because it was not signed.
  2. Not true or correct; based on faulty reasoning.
    • The scientist proved the theory invalid with a simple experiment.
    • That excuse is invalid; you had plenty of time to finish the work.
    • His argument was invalid because it relied on outdated statistics.
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Antonyms
noun
  1. A person who is very weak or sick and needs constant care.
    • The old invalid spent most of the day in bed.
    • After the accident, he became an invalid and could not walk.
    • The nurse cared for the invalid with great patience.