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

IMPAIR definition: 1. to spoil something or make it weaker so that it is less effective: 2. to spoil something or…. Learn more.

To reduce or weaken in strength, quality, etc.... Click for English pronunciations, examples sentences, video.

to make or cause to become worse; weaken; damage: habits that impair one's health.

IMPAIR definition: to make or cause to become worse; diminish in ability, value, excellence, etc.; weaken or damage. See examples of impair used in a sentence.

Definition of impair verb from the Oxford Advanced Learner's Dictionary. impair something to damage something or make something worse. His age impaired his chances of finding a new …

WordReference Random House Learner's Dictionary of American English © 2025 im•pair /ɪmˈpɛr/ v. [~ + object] to make worse; damage: Smoking can impair your health. im•pair•ment, n. …

Dec 11, 2025 · impair (third-person singular simple present impairs, present participle impairing, simple past and past participle impaired) (transitive) To weaken; to affect negatively; to have a …

There are four meanings listed in OED's entry for the word impair, two of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

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 …