leadership or dominance, especially by one state or social group over others. Hegemony, the dominance of one group over another, supported by legitimating norms and ideas. Hegemony is the political, economic, or military predominance or control of one state over others. The dominant state is known as the hegemon. Hegemony definition is - preponderant influence or authority over others : domination. The first is the notion that hegemony entails overwhelming or preponderant material power.