WordWeb Online

1. Of or relating to a magistrate
   "official magisterial functions"
    
2. 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
    
3. Used of a person's appearance or behaviour; befitting an eminent person
   "she reigned in magisterial beauty"
   - distinguished, grand, imposing

See also: dignified, domineering, magisterially, magistrate

Encyclopedia: Magisterial