tyrant

A usurper; one who gains power and rules extralegally, distinguished from kings elevated by election or succession.

To proue him Tyrant, this reason may suffice, That Henry liueth still.

The reappearance of tyranny [in the 4th century BC] had many reasons... one of the main causes was the development of antagonism between rich and poor; tyrants came to power exploiting a social and political imbalance within the state.

Any monarch or governor.

Cassius... set tyrants over all Syria.

A despot; a ruler who governs unjustly, cruelly, or harshly.

Tyrannes...be but Gods scourges which he will cast into the fyre when he hath done with them.

I am the Sonne of Marcus Cato, hoe. A Foe to Tyrants, and my Countries Friend.

Any person who abuses the power of position or office to treat others unjustly, cruelly, or harshly.

A plague vpon the Tyrant that I serue

[…] a sad tyrant, as my friends the Democrats sometimes are.

A villain; a person or thing who uses strength or violence to treat others unjustly, cruelly, or harshly.

I was a blasphemar, and a persecuter, and a tyraunt.

A pike (called the tyranne of fishes).

Tyrannical, tyrannous; like, characteristic of, or in the manner of a tyrant.

He was most tirant & cruell of all emperours.

Thus must I from the smoake into the smother, From tyrant Duke, vnto a tyrant Brother.

To act like a tyrant; to be tyrannical.

Let thy judgment be king, but not tyrant over it

To tyrannize.