A hegemon is a leading or major power. The United States has long been a hegemon in world politics.
If you enjoy an edge over people who would otherwise be your peers, you might be a hegemon: that is, someone who enjoys hegemony, a predominating influence over others. Hegemons are powerful entities. In America, big business is a hegemon. In computers, Apple is a hegemon. For a long time in the NBA, Michael Jordan was a hegemon. Only the powerful can claim to be hegemons. This word suggests dominance and often a little more power than others would prefer.