tsar / zär/ (also czar or tzar) • n. an emperor of Russia before 1917: Tsar Nicholas II. ∎  a South Slav ruler in former times, esp. one reigning over Serbia in the 14th century. ∎ DERIVATIVES: tsar·dom / -dəm/ n.tsar·ism / -ˌizəm/ n.tsar·ist / -ist/ n. & adj.

tsar Name of the rulers of Russia, first adopted by Ivan the Terrible in 1547. It is an adaptation of the Latin caesar. In 1721 Peter I changed the official title to “emperor”, but “tsar” or “czar” continued to be used in popular language until 1917.

tsar an emperor of Russia before 1917. The Russian word tsar represents Latin Caesar; it is first recorded in English in the mid 16th century. In Russia itself it was partially used by the Grand Duke Ivan III (1462–1505) and his son, but was formally assumed by Ivan IV in 1547. The title tsar was also used by Serbian rulers of the 14th century.
Tsarevich was the title of the eldest son of an emperor of Russia.

tsar see CZAR.