a cruel, oppressive use of power
tyranny - oppression
The word ‘tyranny’ is used in two main ways. Firstly, it can refer to a form of government in which a dictator or a small group of people exert total power and control over the population, typically in an unfair, cruel way. Secondly, it can be used in relation to a person or situation that exercises dominance and control over people. In both contexts, the term has only negative connotations.
The new ruler of the country characterized the overthrowing of the former dictator as a victory for freedom over tyranny.
I left that company because I could no longer work for such an overbearing, tyrannical boss. He ran things with an iron fist.
Sarah preferred to be her own boss and go her own way instead of subjecting herself to what she saw as the tyranny of the 9-5 rat race.