What is the meaning of impairment?

noun

• The occurrence of a change for the worse.
  • synonyms: damage, harm
• A symptom of reduced quality or strength.
  • synonyms: deterioration
• The condition of being unable to perform as a consequence of physical or mental unfitness.
  • usage: "reading disability"; "hearing impairment"
  • synonyms: disability, disablement, handicap
• Damage that results in a reduction of strength or quality.
• The act of making something futile and useless (as by routine. ).
  • synonyms: stultification, constipation, deadening