The word menshevik means 'minority'.
Originally part of the Russian Social Democratic Party, split from the Bolsheviks (majority) in 1903, forming two wings of the RSDP, until the Bolsheviks formed a separate party in 1912. They were a moderate socialist party claiming allegiance to Karl Marx, but believed that the working class must collaborate with the liberal bourgeoisie to overthrow czarism and establish a bourgeois democratic republic.