If administrators find out that students cheated on a test, the school might invalidate their class grades. To invalidate means to cancel something or make it void, as if it never happened.

In invalidate you see the word valid which means true or correct. When you invalidate something you are making it less true, less official, or less correct. If you buy something that doesn't work properly and then try to fix it yourself, you invalidate the warranty. If you have a wacky theory that cars grow from trees, your teacher might invalidate your theory by taking you on a tour of an auto factory.

Definitions of invalidate
  1. verb
    make invalid for use
    synonyms: cancel
    see moresee less
    type of:
    mark, score
    make underscoring marks
  2. verb
    declare invalid
    synonyms: annihilate, annul, avoid, nullify, quash, void
    see moresee less
    formalise, formalize, validate
    declare or make legally valid
    invalidate by judicial action
    printing: cancel, as of a correction or deletion
    type of:
    cancel, strike down
    declare null and void; make ineffective
  3. verb
    take away the legal force of or render ineffective
    invalidate a contract”
    synonyms: vitiate, void
    see moresee less
    make valid or confirm the validity of
    type of:
    alter, change, modify
    cause to change; make different; cause a transformation
  4. verb
    show to be invalid
    synonyms: nullify
    see moresee less
    prove valid; show or confirm the validity of something
    type of:
    contradict, negate
    prove negative; show to be false
Word Family

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