General Synonyms:
* Sovereign - This emphasizes the supreme power and authority of the ruler.
* Ruler - A more general term, referring to anyone who holds power over a country.
* Head of State - Focuses on the role the monarch plays in the government.
* King/Queen - More specific terms, depending on the gender of the monarch.
* Emperor/Empress - Used for rulers of empires.
Specific Connotations:
* Regent - Used for a person who rules temporarily in the absence of the monarch.
* Prince/Princess - Refers to a member of a royal family, often heir apparent.
* Autocrat - Emphasizes the absolute power of the monarch.
* Dictator - A more negative term, suggesting that the monarch has seized power by force.
* Tyrant - Used for a cruel and oppressive ruler.
Other Options:
* Leader - A broad term, but can be used in the context of a monarch.
* Chief - This term is less formal and can be used for a leader of a tribe or small group.
The best synonym for "monarch" will depend on the specific situation and the nuance you want to convey.