czar also tsar or tzar 
/ˈzɑɚ/ noun
plural czars also tsars or tzars /ˈzɑɚ/ noun [count] 1 : the title of the ruler of Russia before 1917
▪ Russia's Czar Nicholas II 2 chiefly US a : a very powerful person in a particular business or activity
▪ a banking czar
b — used as an unofficial title for the person who is in charge of a government office or department ▪ The President has appointed a new drug czar. ▪ the education/housing/terrorism czar
▪ Russia's Czar Nicholas II
▪ a banking czar
b — used as an unofficial title for the person who is in charge of a government office or department ▪ The President has appointed a new drug czar. ▪ the education/housing/terrorism czar
