1.
captain; team leader; commander-in-chief
The leader or captain of a sports team, or historically the chief commander of an army. In modern usage, most commonly refers to a team captain in sports.
Usage
主将 is used in sports contexts for the team captain, the player who leads the team and often serves as the representative in ceremonies. In baseball, the 主将 is distinct from the 監督 (manager). In historical contexts, it refers to the supreme commander of an army.
Similar words
キャプテン (captain) is the loanword equivalent used more casually. 副主将 is the vice-captain.