Tyrannical (adjective)

1. Of or like a tyrant; absolute and oppressive; despotic; unjustly severe; as, a tyrannical government; a tyrannical command; a tyrannical law.
2. Given to the use of tyranny; as, a tyrannical man.

Origin:

From late latin tyrannicalis, from latin tyrannus ("tyran.t")

Examples:

1. The tyrannical ruler banned all forms of dissent.
2. His tyrannical behavior made him many enemies.
3. The tyrannical king would not tolerate any opposition.
4. The employees were treated in a tyrannical manner by their boss.
5. Tyrannical leaders will always fall in the end.