invalid in WordNet English dictionary

1. injure permanently
   "He was disabled in a car accident"
   disable  invalid  incapacitate  handicap 
   
2. force to retire, remove from active duty, as of firemen
   invalid 
   

1. someone who is incapacitated by a chronic illness or injury
   invalid  shut-in 
   

1. having no cogency or legal force
   "invalid reasoning"; "an invalid driver's license"
   invalid 
   
2. no longer valid
   "the license is invalid"
   invalid