- (transitive) to reduce or weaken in strength, quality, etc: his hearing was impaired by an accident
WordReference Random House Learner's Dictionary of American English © 2026
im•pair /ɪmˈpɛr/USA pronunciation
v. [~ + object]
WordReference Random House Unabridged Dictionary of American English © 2026- to make worse;
damage:Smoking can impair your health.
im•pair
(im pâr′),USA pronunciation v.t.
v.i.
n.
im•pair′a•ble, adj.
im•pair′er, n.
im•pair′ment, n.
im•pair (an per′),USA pronunciation adj. [French.]
- to make or cause to become worse;
diminish in ability, value, excellence, etc.;
weaken or damage:to impair one's health; to impair negotiations.
v.i.
- to grow or become worse;
lessen.
n.
- [Archaic.]impairment.
- Late Latin pējōrāre, equivalent. to Latin pējōr-, stem of pējor worse + -ā- thematic vowel + -re infinitive suffix; compare pejorative
- Middle French empeirer, equivalent. to em- im-1 + peirer to make worse
- Middle English empairen, empeiren to make worse 1250–1300
im•pair′er, n.
im•pair′ment, n.
- 1. See injure.
- 1. repair.
im•pair (an per′),USA pronunciation adj. [French.]
- noting any odd number, esp. in roulette. Cf. pair.
Collins Concise English Dictionary © HarperCollins Publishers::
impair /ɪmˈpɛə/ vb
'impair' also found in these entries (note: many are not synonyms or translations):
alloy
- anticoagulant
- mar
- poison
- protease inhibitor
- shatter
- ACTH
- amidinohydrazone
- blemish
- blindfold
- blunt
- break
- corrode
- craze
- cripple
- damage
- derogate
- honor
- hurt
- impaired
- injure
- invalidate
- maim
- nonimpairment
- overbear
- pair
- pervert
- preimpair
- preimpairment
- riddle
- rust
- treason
- unimpairable
- virgin birth
- vitiate
- weaken
- wear
- wreck
- sap
- self-impairable
- self-impairing
- spoil
- strain