均势 (jūn shì) literally combines 均 (jūn), meaning 'even', 'equal', or 'balanced', and 势 (shì), meaning 'power', 'force', or 'influence'. Together, they denote a state in which opposing sides—whether nations, political groups, or competing forces—hold roughly equal strength, preventing any one side from dominating. It is a formal, abstract term most commonly used in political science, international relations, history, and strategic analysis.

The concept emphasizes dynamic stability rather than static equality: a balance of power can shift over time but remains functional as long as no single actor gains decisive advantage. While often applied to geopolitics (e.g., Cold War US–Soviet relations), it also appears in business strategy, military theory, and even ecological discussions about competing species or environmental pressures. It carries a neutral-to-slightly formal register and rarely appears in casual speech.