The word 首席 is formed by combining two characters, each contributing a concrete image to create an abstract meaning. The first character, 首, means "head", evoking the idea of the foremost or leading part. The second, 席, means "mat" or "seat", representing a place of gathering or position. When combined, they create a powerful conceptual metaphor: the "head seat", which visually and intuitively signifies the foremost position, such as the seat of the leader, the top performer, or the principal holder of a title.