Source : Webster's Revised Unabridged Dictionary (1913)

Impairment \Im*pair"ment\, n. [OE. enpeirement, OF. empirement.]
   The state of being impaired; injury. ``The impairment of my
   health.'' --Dryden.

Source : WordNet®

impairment
     n 1: the occurrence of a change for the worse [syn: {damage}, {harm}]
     2: a symptom of reduced quality or strength [syn: {deterioration}]
     3: the condition of being unable to perform as a consequence of
        physical or mental unfitness; "reading disability";
        "hearing impairment" [syn: {disability}, {disablement}, {handicap}]
     4: damage that results in a reduction of strength or quality
     5: the act of making something futile and useless (as by
        routine) [syn: {stultification}, {constipation}, {deadening}]