impair

1 of 2

verb

im·​pair im-ˈper How to pronounce impair (audio)
impaired; impairing; impairs
Synonyms of impair

transitive verb

: to diminish in function, ability, or quality : to weaken or make worse
It has been known for nearly 100 years that memory is impaired by bilateral damage to either of two brain regions …—Larry R. Squire
The use of drugs further complicates the situation of these families and sometimes impairs their ability to raise children.—Ellen L. Bassuk
… the prospect of generating normal profitability is impaired by excessive debt service.—John Nozell
The physician also checks for signs of endometriosis, a condition … sometimes impairing fertility.—Martha Southgate
impairer noun
… the overwhelming majority of hookups involved alcohol use—an impairer of sexual judgment if ever there was one … —Tiffany Sharples

impairer

2 of 2

noun

im·​pair·​er
-rə(r)
plural -s
: one that impairs
lack of confidence is often an impairer of efficiency

Synonyms of impair

Relevance

Verb

See All Synonyms & Antonyms in Thesaurus
Choose the Right Synonym for impair

injure, harm, hurt, damage, impair, mar mean to affect injuriously.

injure implies the inflicting of anything detrimental to one's looks, comfort, health, or success.

badly injured in an accident

harm often stresses the inflicting of pain, suffering, or loss.

careful not to harm the animals

hurt implies inflicting a wound to the body or to the feelings.

hurt by their callous remarks

damage suggests injury that lowers value or impairs usefulness.

a table damaged in shipping

impair suggests a making less complete or efficient by deterioration or diminution.

years of smoking had impaired his health

mar applies to injury that spoils perfection (as of a surface) or causes disfigurement.

the text is marred by many typos

Examples of impair in a Sentence

Verb Smoking can impair your health. Drinking impairs a person's ability to think clearly. His memory was so impaired by age that he often forgot where he was.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Verb
Cold water shock impairs breathing and can overwhelm even strong swimmers within seconds. — Kara Fox, CNN Money, 28 June 2026 What can permanently impair the value? — Jim Osman, Forbes.com, 25 June 2026 Nampa Police, which is investigating the incident, said the driver wasn’t impaired. — Alex Brizee, Idaho Statesman, 22 June 2026 That match carries a 70% probability of performance-impairing heat. — Carlos Roa, The Orlando Sentinel, 25 June 2026 See All Example Sentences for impair

Word History

Etymology

Verb

Middle English empeiren, from Anglo-French empeirer, from Vulgar Latin *impejorare, from Latin in- + Late Latin pejorare to make worse — more at pejorative

First Known Use

Verb

14th century, in the meaning defined above

Time Traveler
The first known use of impair was in the 14th century

Rhymes for impair

See All Rhymes for impair

Browse Nearby Words

impaint
impair
impairable
See all Nearby Words

Cite this Entry

“Impair.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/impair. Accessed 7 Jul. 2026.

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Kids Definition

impair

verb
im·​pair im-ˈpa(ə)r How to pronounce impair (audio)
-ˈpe(ə)r
: to damage or make worse by or as if by making smaller, less, or weaker
smoking can impair one's health
impairment
-mənt How to pronounce impair (audio)
noun

Medical Definition

impair

transitive verb
im·​pair im-ˈpa(ə)r, -ˈpe(ə)r How to pronounce impair (audio)
: to diminish in function, ability, or quality : to weaken or make worse
It has been known for nearly 100 years that memory is impaired by bilateral damage to either of two brain regions …—Larry R. Squire
The physician also checks for signs of endometriosis, a condition in which the cells that normally compose the uterine lining grow outside the uterus, sometimes impairing fertility.—Martha Southgate
impairment
-ˈpa(ə)r-mənt How to pronounce impair (audio)
noun

Legal Definition

impair

transitive verb
im·​pair im-ˈper How to pronounce impair (audio)
1
: to damage or make worse by or as if by diminishing
impaired health
2
: to diminish the value of (property or property rights)
specifically : to diminish the value of (legal contractual obligations) to the point that a party loses the benefit of the contract or the contract otherwise becomes invalid
a law impairing a state's own obligations was entitled to less deference —Gerald Gunther
see also contract clause
impairment noun

More from Merriam-Webster on impair

Nglish: Translation of impair for Spanish Speakers

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