adjective offensively self-assured or given to exercising usually unwarranted power.
— synonyms: bossy, dominating, high-and-mighty, magisterial, peremptory
adjective characteristic of an absolute ruler or absolute rule.
— synonyms: authoritarian, dictatorial, despotic, tyrannic, tyrannical
Examples
“In recent years, the prime minister has become increasingly autocratic.”
“Despite his lack of actual authority, his autocratic demeanour annoyed many of his colleagues.”