Impair \Im*pair"\, v. t. [imp. & p. p. Impaired; p. pr. & vb. n. Impairing.]

[Written also empair.]

[OE. empeiren, enpeiren, OF. empeirier, empirier, F. empirer, LL. impejorare; L. pref. im- in + pejorare to make worse, fr. pejor worse. Cf. Appair.]

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.

Source: Webster's Revised Unabridged Dictionary (1913)