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.

verb (used without object)

to grow or become worse; lessen.


Archaic. impairment.

Origin of impair

1250–1300; Middle English empairen, empeiren to make worse < Middle French empeirer, equivalent to em- im-1 + peirer to make worse < Late Latin pējōrāre, equivalent to Latin pējōr-, stem of pējor worse + -ā- thematic vowel + -re infinitive suffix; cf. pejorative
Related formsim·pair·a·ble, adjectiveim·pair·er, nounim·pair·ment, nounnon·im·pair·ment, nounpre·im·pair·ment, nounself-im·pair·a·ble, adjectiveself-im·pair·ing, adjectiveun·im·pair·a·ble, adjective

Synonyms for impair

1. See injure.

Antonyms for impair

1. repair. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for impairing

Historical Examples of impairing

  • I will not do my family the injury of impairing the little I have.

    Albert Gallatin

    John Austin Stevens

  • The money was her husband's, and you knew it, and you knew it was impairing his estate to furnish it.

    Gordon Keith

    Thomas Nelson Page

  • The caution increased his cunning but was impairing his character.

    The Young Man and the World

    Albert J. Beveridge

  • Emerson has used the same figure, but in a passage which ought not to be regarded as impairing our author's originality.

  • By these means I was enabled to reserve all my rents for carrying on my lawsuits, without at all impairing the estate.

    Rattlin the Reefer

    Edward Howard

British Dictionary definitions for impairing



(tr) to reduce or weaken in strength, quality, etchis hearing was impaired by an accident
Derived Formsimpairable, adjectiveimpairer, nounimpairment, noun

Word Origin for impair

C14: from Old French empeirer to make worse, from Late Latin pējorāre, from Latin pejor worse; see pejorative
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

Word Origin and History for impairing



late 14c., earlier ampayre, apeyre (c.1300), from Old French empeirier (Modern French empirer), from Vulgar Latin *impeiorare "make worse," from assimilated form of in- "into, in" (see in- (2)) + Late Latin peiorare "make worse" (see pejorative). In reference to driving under the influence of alcohol, first recorded 1951 in Canadian English. Related: Impaired; impairing.

Online Etymology Dictionary, © 2010 Douglas Harper