Tyrant
Part of speech: noun
Definition: An absolute ruler who governs without restriction. A harsh and cruel ruler. An oppressive, cruel and harsh person.
Example sentence: The tyrant dies and his rule is over, the martyr dies and his rule begins.
Despot
Part of speech: noun
Definition: A ruler with absolute power; a tyrant.A title awarded to senior members of the imperial family in the late Byzantine Empire, and claimed by various independent or semi-autonomous rulers in the Balkans (12th to 15th centuries)
Example sentence: Bush II's democracy crusade and Obama's embrace of the Arab Spring have unleashed and empowered forces less receptive to America's wishes and will than the despots and dictators deposed with our approval.