Czar
Part of speech: noun
Definition: A Slavic emperor (not necessarily a Russian emperor) A high-rank political official of the executive branch: “drug czar”.
Example sentence: In 1817, Czar Alexander I personally founded the Society of Israelite Christians but had less luck defeating Judaism than he'd had defeating Napoleon; gentile serfs and merchants in areas bordering the Pale even showed disturbing new signs of 'Judaizing.'
Tsar
Part of speech: noun
Definition: A Slavic emperor (not necessarily a Russian emperor)A person with great power; an autocratAn appointed official tasked to regulate or oversee a specific area