Im·pair v. t. [imp. & p. p. Impaired p. pr. & vb. n. Impairing.] [Written also empair.] To make worse; to diminish in quantity, value, excellence, or strength; to deteriorate; as, to impair health, character, the mind, value.
Time sensibly all things impairs. --Roscommon.
In years he seemed, but not impaired by years. --Pope.
Syn: -- To diminish; decrease; injure; weaken; enfeeble; debilitate; reduce; debase; deteriorate.