autocratic

Of or pertaining to autocracy or to an autocrat; absolute; holding independent and arbitrary powers of government. -- Au·to·crat·ic·al·ly, adv.

adjective

1. Having and exercising complete political power and control: absolute, absolutistic, arbitrary, autarchic, autarchical, autocratical, despotic, dictatorial, monocratic, totalitarian, tyrannic, tyrannical, tyrannous. See over/under, politics.
2. Characterized by or favoring absolute obedience to authority: authoritarian, despotic, dictatorial, totalitarian, tyrannic, tyrannical. See over/under.

The adjective has 4 meanings:

Meaning #1: of the nature of or relating to an autocrat
  Synonym: autocratical
  Pertains to noun: autocrat (meaning #1)

Meaning #2: relating to or of the nature of or having characteristics of an autocracy
  Synonym: autocratical
  Pertains to noun: autocracy (meaning #1)

Meaning #3: offensively self-assured or given to exercising usually unwarranted power
  Synonyms: bossy, dominating, high-and-mighty, magisterial, peremptory

Meaning #4: characteristic of an absolute ruler or absolute rule; having absolute sovereignty
  Synonyms: authoritarian, dictatorial, despotic, tyrannical