Supremacy means being the most powerful, important, or dominant in a particular area. When a team has supremacy in their league, they're clearly the best, winning more games and outperforming everyone else. When a country achieves naval supremacy, its navy is stronger than all others.

The word suggests being at the very top, above all competitors or rivals. You might read about a company's supremacy in smartphone sales, meaning they sell more phones than any other company. A chess champion who defeats all challengers has established supremacy in the chess world.

Supremacy describes dominance in sports, business, military power, or technology. During the Space Race of the 1960s, the United States and Soviet Union competed for supremacy in space exploration, each trying to prove their rockets and technology were superior.

The word often appears in discussions of power and competition. When scientists debate which species has supremacy in an ecosystem, they're asking which one is most successful and influential in that environment.