The verb impair is to weaken or diminish the value, quality, or function of something.

Synonyms are blemish, damage, deface, or disfigure.

The word origins from a re-Latinizing (c. 1300) of earlier ampayreapeyre meaning “make worse, cause to deteriorate” and from Old French empeirier meaning “make worse” (Modern French empirer). It also origins from Vulgar Latin impeiorare “make worse”. Its first known use is in the 14th century.

Alcohol impairs our judgement and ability to think straight so never drink beyond your limit.

Too much use of computers without an anti-blue light glasses will impair your vision.

Not having enough sleep could impair one’s memory.