Dictator (noun)

1. A ruler with total power over a country, typically one who has obtained power by force.
2. A person with complete control over a situation or activity.
3. A person who behaves in an autocratic or domineering way.

Origin:

Late 16th century: from latin dictator, from dictare "speak", from dic- "said" + -tor "-ator".

Examples:

1. He was a dictator who ruled with an iron fist.
2. The country was ruled by a dictator for many years.
3. The dictator was finally overthrown in a popular uprising.
4. The coach is a dictator on the field.
5. He was a dictator in his own home.