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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.

One doctor never examined her, while another barely spoke to her; either of these issues could invalidate competency declarations and expose medical misconduct, fraud and/or conspiracy.

From MarketWatch • Mar. 19, 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

Two years later, Silverstein persuaded a judge to invalidate the building permits for a 299-unit high-rise on Sunset Boulevard.

From Los Angeles Times • Dec. 2, 2025

“Like, that doesn’t invalidate it, right? Your parents can get divorced and it doesn’t mean anything in the long run.”

From "Far from the Tree" by Robin Benway