Synonyms

impair

¹ American

[im-pair] / ɪmˈpɛər /

verb (used with object)

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)

to grow or become worse; lessen.

noun

Archaic. impairment.

impair ² American

[an-per] / ɛ̃ˈpɛr /

adjective

French.

noting any odd number, especially in roulette.

impair British

/ ɪmˈpɛə /

verb

(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

Synonym Usage

See injure.

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

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”; cf. 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. )

Explanation

If you make bad decisions in the morning after drinking coffee, you might conclude that caffeine tends to impair your judgment. When you impair something, you damage it or make it work poorly. The root of the verb impair traces back to the Latin word pejorare, meaning “to make worse,” and that’s still what happens if you impair something. Whether it’s communication, visibility, or your marriage prospects, if you impair it, you make it worse. The word can be used for situations that describe something that has deteriorated, such as “Snow continued to impair driving conditions.”

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Vocabulary lists containing impair

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United States v. Nixon (1974)

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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.

See Examples For:

impair impairs impaired impairing

She said the scale, height, and mass of the new ballroom would impair her aesthetic, cultural, and historical interests in viewing and appreciating the White House.

From Slate ● Sep. 1, 2026

"One of my takeaway conclusions from the Science paper was that many Greenland sharks have parasites attached to their eyes -- which could impair their vision," she says.

From Science Daily ● Aug. 23, 2026

“Gondola cars encased in digital ads, flying 26 feet overhead every 25-30 seconds would irreparably impair the vista, and the sense of calm and escape from urban life,” wrote former state parks director Ruth Coleman.

From Los Angeles Times ● Aug. 1, 2026

China aims to match the U.S. as the world’s leading space power and is catching up fast, especially when it comes to satellites—giving Beijing the potential to impair rival networks and blunt U.S. military might.

From The Wall Street Journal ● Jul. 29, 2026

In the earlier discussion, however, I was referring to things that impair our ability to solve problems.

From "Blink" by Malcolm Gladwell

"Abdominal obesity reduces circulating vitamin D, and that deficiency impairs the immune system, exacerbating the chronic inflammation caused by excess fat and drastically increasing the risk of mortality," Alexandre explains to Agência FAPESP.

From Science Daily ● Aug. 14, 2026

This impairs our ability to quickly shed excess heat and makes it harder to judge when our bodies are under burden, simply because we can't see as much sweat on our skin or clothing.

From BBC ● Jul. 8, 2026

But as her mom’s care needs progressed, Valencia began providing 24-hour care for her mother, who also suffers from aphasia — a language disorder that impairs speaking, understanding, reading and writing.

From MarketWatch ● Jun. 16, 2026

High blood sugar impairs immune function and narrows vessels that carry oxygen-rich blood, making it harder for skin to heal.

From Los Angeles Times ● Jun. 14, 2026

This blindness impairs us in every act of communication.

From "The Sense of Style" by Steven Pinker

It blamed an "unusual confluence of developments that has impaired investor confidence in the market for new public offerings".

From BBC ● Sep. 29, 2026

Archuleta, whose granddaughter was killed by an impaired driver, said working to turn the bill into law was a personal fight for him.

From Los Angeles Times ● Sep. 25, 2026

With the pipeline impaired, Saudi Arabia is increasingly relying on its Persian Gulf export terminals to keep crude moving through Hormuz.

From The Wall Street Journal ● Sep. 21, 2026

When these local connections showed poorer integrity, gray matter loss was more strongly associated with impaired language performance and broader cognitive difficulties.

From Science Daily ● Sep. 14, 2026

He’s so tall, too, that she has to crane her neck to make a safe turn because her visibility is impaired.

From "A Heart in a Body in the World" by Deb Caletti

The Cheshire native suffered a stroke in 2013, impairing his ability to walk.

From Los Angeles Times ● Aug. 26, 2026

“This highlights a new order and durability of oil/energy risks as the war transitions, notably, from temporary disruptions to more lasting capacity destruction impairing the production and passage of oil and gas,” Varathan said.

From The Wall Street Journal ● Mar. 19, 2026

“In particular, how effective drones are in impairing production and transportation of crude via the Strait of Hormuz.”

From MarketWatch ● Feb. 28, 2026

Oneglia: Having deeper capital markets with a more developed pension sector can help finance some of Europe’s policy priorities, such as infrastructure, without impairing national budgets.

From Barron's ● Nov. 20, 2025

This is because the act of describing a face has the effect of impairing your otherwise effortless ability to subsequently recognize that face.

From "Blink" by Malcolm Gladwell

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