Tyrant
WordNet
noun
(1) A cruel and oppressive dictator
(2) Any person who exercises power in a cruel way
"His father was a tyrant"
(3) In ancient Greece, a ruler who had seized power without legal right to it
WiktionaryText
Etymology
From tyrant from tyrannus, from .
Noun
- An absolute ruler who governs without restriction.
- A harsh and cruel ruler.
- An oppressive, cruel and harsh person.