A person who is weak and infirm; one who is disabled for active service; especially, one in chronic ill health who is unable to care for himself, Any person with a disability, verb_ force to retire, remove from active duty, as of firemen, injure permanently, transitive verb_ To make or render invalid or infirm, To classify or enroll as an invalid, someone who is incapacitated by a chronic illness or injury, One who is confined to home or bed because of illness, disability or injury