Tyranny

Noun

1. A government in which a single ruler (a tyrant) has absolute power, or this system of government; especially, one that acts cruelly and unjustly.
2. The office or jurisdiction of an absolute ruler.
3. Absolute power, or its use.
4. A system of government in which power is exercised on behalf of the ruler or ruling class, without regard to the wishes of the governed.
5. Extreme severity or rigour.