In Liangshan folklore, the ancient city said to have sunk to the bottom of the lake in the "Subsidence of Qionghai Lake" legend is referred to as "Zitong County". This name bears no geographical connection to Xichang and differs from the names given to the sunken city in historical documents of successive dynasties, such as "Qiongdu", "Xianhe" and "Qiongchi". With the rise of the Wenchang-Zitong faith, as a linguistic symbol imbued with sacred power, "Zitong" gained naming legitimacy through the expansive force of faith narratives. Upon entering the oral cultural context of Liangshan, it detached from the original form and meaning of written characters as well as its geographical and religious connotations, degenerating into the purely phonetic symbol "zǐ tóng". Based on local life experiences and situational associations, the people endowed it with new meanings such as "purple copper", "catalpa and tung tree", thereby localizing it. This process reveals that while written characters maintain the stability of names, they remain detached from the oral world; linguistic symbols possess powerful expansive force yet depend on specific cultural knowledge and contexts; and speech sounds, with their audible and associative characteristics, become the key force enabling legends to take root among the people.