Bolshevik UK /ˈbɒlʃəvɪk/US /ˈboʊlʃəvɪk/ noun2 •(historical) A Russian communist revolutionary, a member of the Bolshevik Party in the Communist Revolution of Russia in 1917. •(historical) A member of the Communist Party that ruled the Russian Soviet Federative Socialist Republic and the Union of Soviet Socialist Republics. formsBolsheviki · Bolsheviks · bolsheviki · bolsheviks