Definition of "impair" in English

verb

1. (transitive) To weaken; to affect negatively; to have a diminishing effect on.

2. (intransitive, archaic) To grow worse; to deteriorate.

adjective

1. (obsolete) Not fit or appropriate; unsuitable.

noun

1. (obsolete) The act of impairing or deteriorating.

2. (obsolete) The fact of being impaired or having grown worse.

3. (obsolete) An impairment or deterioration.