"Tang Yun" and "Ji Yun" state: Ancient *xue* (falling tone) cut, pronounced the same as *jue*. "Shuowen Jiezi" explains it as: making the eyes bright. "Guang Yun" explains it as: having eye problems. Also, "Ji Yun" states: *hu jue* (falling tone) cut, pronounced the same as *xue*. The meaning is: to look with fright. It also refers to the appearance of a wandering gaze. There is a sentence in "Wang Sun Fu" by Wang Yanshou: "Shi jie yi zhan mu." "Ji Yun" states: it is the same as the character "xue." "Sui Yuan" states: it is used interchangeably with the character "". "Shuowen Jiezi" was originally written as "", the character's form is from "mu" (eye), and "guai" indicates the pronunciation. "Xu Xuan Shuo" should be considered to be derived from the character "jue" with an omission. The character "" is composed of "mu" (eye) and "kuai."