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Synonyms

invalidate

American  
[in-val-i-deyt] / ɪnˈvæl ɪˌdeɪt /

verb (used with object)

invalidated, invalidating
  1. to render invalid; discredit.

    Synonyms:
    rebut, refute, disprove, impair, weaken
  2. to deprive of legal force or efficacy; nullify.


invalidate British  
/ ɪnˈvælɪˌdeɪt /

verb

  1. to render weak or ineffective, as an argument

  2. to take away the legal force or effectiveness of; annul, as a contract

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • invalidation noun
  • invalidator noun

Etymology

Origin of invalidate

First recorded in 1640–50; invalid 2 + -ate 1

Explanation

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.

Keep Reading on Vocabulary.com

Vocabulary lists containing invalidate

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A finding of undue influence can invalidate a will or trust if your grandmother was pressured, manipulated or dependent on your mother.

From MarketWatch • Mar. 30, 2026

They say the new guidance violates multiple federal laws, including laws that govern federal spending and rule changes, and are asking the federal court to immediately invalidate the guidance as unlawful.

From Los Angeles Times • Mar. 16, 2026

US District Judge Royce Lamberth endorsed Revolution Wind's request to invalidate the US Interior Department's move to suspend the project off the coast of Rhode Island.

From Barron's • Jan. 12, 2026

In 2022, however, the American Journal of Therapeutics, which had published the study, warned that suspicious data “appears to invalidate the findings” regarding ivermectin’s potential to decrease deaths.

From Salon • Dec. 15, 2025

The half-broken mini blind that would surely invalidate their deposit if they ever moved out.

From "We'll Fly Away" by Bryan Bliss