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Synonyms

impair

1 American  
[im-pair] / ɪmˈpɛər /

verb (used with object)

  1. to make or cause to become worse; diminish in ability, value, excellence, etc.; weaken or damage.

    to impair one's health;

    to impair negotiations.
    Antonyms:
    repair

verb (used without object)

  1. to grow or become worse; lessen.

noun

  1. Archaic. impairment.

impair 2 American  
[an-per] / ɛ̃ˈpɛr /

adjective

French.

  1. noting any odd number, especially in roulette.

impair British  
/ ɪmˈpɛə /

verb

  1. (tr) to reduce or weaken in strength, quality, etc

    his hearing was impaired by an accident
"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

Related Words

See injure.

Other Word Forms

  • impairable adjective
  • impairer noun
  • impairment noun
  • nonimpairment noun
  • preimpairment noun
  • self-impairable adjective
  • self-impairing adjective
  • unimpairable adjective

Etymology

Origin of impair1

First recorded in 1250–1300; Middle English empairen, empeiren “to make worse,” from Middle French empeirer, from em- im- 1 + peirer “to make worse” (from Late Latin pējōrāre, verb derivative of Latin pējor “worse”; pejoration )

Origin of impair2

First recorded in 1820–30; from French: literally, “odd,” from Latin impār “odd, unequal”; equivalent to im- 2 ( def. ) + pair 2 ( def. )

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.

She wrote that the majority’s ruling “opens a dangerous can of worms” that “threatens to impair states’ ability to regulate the provision of medical care in any respect.”

From Salon • Mar. 31, 2026

The centre's chief executive, Jackie Rodriguez, told the BBC that dyslexia does not impair a person's intelligence, judgement or ability to lead.

From BBC • Mar. 16, 2026

On the flip side, the Fed might be more inclined to cut rates if higher oil prices were to impair the U.S. economy, raise layoffs or cause companies to hire even less.

From MarketWatch • Mar. 10, 2026

Rarely used against a U.S. company, the move—if it survives Anthropic’s expected legal challenge—could impair Anthropic’s ability to work with other government contractors including Lockheed Martin, Amazon and Microsoft.

From The Wall Street Journal • Mar. 3, 2026

Hadn’t the duke given her enough bloodbane to seriously impair the assassin?

From "Throne of Glass" by Sarah J. Maas

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.