lawful in WordNet English dictionary

1. conformable to or allowed by law
   "lawful methods of dissent"
   lawful 
   
2. authorized, sanctioned by, or in accordance with law
   "a legitimate government"
   lawful  legitimate  licit 
   
3. having a legally established claim
   "the legitimate heir"; "the true and lawful king"
   true  lawful  rightful 
   
4. according to custom or rule or natural law
   lawful  rule-governed