1550s, from Russian tsar, from Old Slavic tsesari, from Gothic kaisar, from Greek kaisar, from Latin Caesar. First adopted by Russian emperor Ivan IV, 1547.
The Germanic form of the word also is the source of Finnish keisari, Estonian keisar. The transferred sense of "person with dictatorial powers" is first recorded 1866, American English, initially in reference to President Andrew Johnson. The fem. czarina is 1717, from Italian czarina, from Ger. Zarin, fem. of Zar "czar." The Russian fem. form is tsaritsa. His son is tsarevitch, his daughter is tsarevna