impair
im-PAIRverbMeaning to damage or weaken
Memory hook im-PAIR: a smudged PAIR of glasses. Grandpa’s pair of glasses is smeared with jam, and now he can barely read the paper. The smudges impair his sight.
Very loud music can impair your hearing over time.
In context Thick fog impaired the drivers’ view so badly that the town closed the bridge until it lifted at noon.
Similar damage, weaken, harm, diminish
Opposite improve, enhance, strengthen
From Old French empeirier, “to make worse,” based on Latin pejor, worse.