WordNet sense 1 (marked by unjust severity or arbitrary behavior):

oppressive, tyrannical

WordNet sense 2 (able to deal authoritatively with affairs):

imperious, masterful

WordNet sense 3 (given to haughty disregard of others):

high-handed

WordNet sense 4 (noisily domineering; tending to browbeat others):

bullying

WordNet sense 5 (offensively self-assured or given to exercising usually unwarranted power):

autocratic, bossy, peremptory

WordNet sense 6 (expecting unquestioning obedience):

overbearing