The word "嵊泗" is formed by combining two characters: "嵊", which is composed of the mountain radical "山" atop the component "乘" primarily for phonetic indication, denoting a mountainous area, and "泗", which consists of the water radical "氵" alongside "四" for sound, representing water. Together, they create a toponym that describes a geographical location featuring both mountains and water, specifically referring to the Shengsi islands.