Absolute, autocratic, arbitrary, despotic and tyrannical all mean exercising power or authority without restraint.
- He ruled with absolute power.
Autocratic suggests the egotistical, self-conscious use of power or the haughty imposition of one’s own will.
- The president resigned after 30 years of autocratic rule.
Arbitrary implies the exercise and usually the abuse of power according to one’s momentary inclination.
- The company has been the subject of an arbitrary take-over.
Despotic implies the arbitrary and imperious exercise of absolute power or control.
- The country was ruled by a despotic tyrant.
Tyrannical implies the abuse of absolute power and harsh or oppressive rule. (see also: Tyrannical yolk vs Tyrannical yoke )
- In the end she left home just to escape the tyrannical rule of her mother.