Slavic word for "vengeance" (Polish: mscic, Czech: mstít, Ukrainian: mstiti), while "woj" or "wój" means "warrior".

Thus the name has meaning "Avenger of warriors" or "Avenger warrior". Another forms of the name are: Mistivir, Mistiuis, Mistui, Mistuwoi, Mistiwoi, Mystiwoi, Mistivoj, Mstivoj and Polish Msciwój. The Christian name of Mstivoj was Billung - baptised after his probable