Domination of a particular social group, nation or political entity over others. In the post war area, the Soviet Union was commonly referred to as having hegemony over Eastern Europe and the Warsaw Pact nations. The word comes from the Greek 'hegemon', or 'leader'. Hegemony can also be applied to ideological groupings, in the sense that communism had ideological hegemony over Marxism, and other byproducts of the communist pantheon of ideologies.