- (in Russia)
- a member of the more radical majority of the Social Democratic Party, 1903–17, advocating immediate and forceful seizure of power by the proletariat.
- (after 1918) a member of the Russian Communist Party.
- (loosely) a member of any Communist party.
- a contemptuous term used to refer to an extreme radical or revolutionary.
- (formerly) a Russian Communist
- any Communist
- any political radical, esp a revolutionary