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

The committee typically engages such tools if a clear market-functioning or financial-stability risk threatens to impair monetary policy, a bar that current conditions don’t appear to meet.

From The Wall Street Journal ● Aug. 4, 2026

The effects may not be immediate, she says, but over time they can impair growth, learning and immunity.

From BBC ● Jul. 4, 2026

Dementia is an umbrella term for debilitating symptoms that can result in memory loss and impair movement and daily life.

From Barron's ● Jun. 15, 2026

Additional evidence from clinical guidelines and research on wound healing and glycemic control also points to the same conclusion: high blood sugar can impair immune function and slow tissue repair.

From Science Daily ● May 16, 2026

With a logic problem, asking people to explain themselves doesn’t impair their ability to come up with the answers.

From "Blink" by Malcolm Gladwell

This damage impairs the ability of nerves to carry electrical messages from the brain to the rest of the body - including those needed for the precise control of muscles needed to walk.

From BBC ● Jul. 22, 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

That may or may not come to pass, but how we behave around others either impairs or enhances our reputation.

From MarketWatch ● Apr. 7, 2026

"We found that, contrary to popular belief, closing one's eyes actually impairs the ability to detect these sounds," said author Yu Huang.

From Science Daily ● Mar. 20, 2026

This blindness impairs us in every act of communication.

From "The Sense of Style" by Steven Pinker

According to the Palo Alto police department, the other driver was uninjured, neither driver was impaired and no one was cited.

From Los Angeles Times ● Jul. 28, 2026

Rob Moulds, 57, from Birmingham, is visually impaired and uses a cane when walking.

From BBC ● Jul. 22, 2026

The court heard that Zambada suffered from several health conditions and would need treatment in custody, with Judge Cogan describing him as "drifting towards cognitively impaired."

From Barron's ● Jul. 20, 2026

Every participant had impaired kidney function along with elevated levels of protein in the urine, which is a key warning sign that kidney damage may continue to worsen.

From Science Daily ● Jul. 16, 2026

Instead of turning my oxygen off, Harris, in his hypoxically impaired state, had mistakenly cranked the valve open to full flow, draining the tank.

From "Into Thin Air" by Jon Krakauer

Cedars-Sinai spokesperson Duke Helfand said the hospital would be unable to recruit and retain physicians, nurses, and specialists if the measure passed, dramatically impairing its ability to provide healthcare.

From Los Angeles Times ● Jun. 10, 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