tyranny

noun5

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. •
   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.

   • He that with shepheards and a litle spoyle, Durst in disdaine of wrong and tyrannie, Defend his freedome gainst a Monarchie: What will he doe supported by a king? — 1587
3. •
   Absolute power, or its use.
4. •
   Extreme severity or rigour.
5. •
   The office or jurisdiction of an absolute ruler.