Impair

Webster's Dictionary of the English Language

·noun Diminution; injury.

II. Impair ·adj Not fit or appropriate.

III. Impair ·vt To grow worse; to Deteriorate.

IV. Impair ·vt To make worse; to diminish in quantity, value, excellence, or strength; to Deteriorate; as, to impair health, character, the mind, value.