WordWeb Online

1. Offensively self-assured or given to exercising usually unwarranted power
   "managed the employees in an aloof magisterial way";
   - autocratic, bossy, dominating, high-and-mighty, peremptory
    
2. Used of a person's appearance or behaviour; befitting an eminent person
   "she reigned in magisterial beauty";
   - distinguished, grand, imposing
    
3. Of or relating to a magistrate
   "official magisterial functions"

See also: dignified, domineering

Encyclopedia: Magisterial