1) XieShe SiDeng KaiKou Qiyunzi 蟹摄四等开口齐韵字2) the fourth category (mouth open or closed) of the middle ancient rhymes 开合口四等韵3) the first grade in Dang-She Kaikou words 宕摄开口一等唐部字4) the first category (mouth open or closed) of the middle ancient rhymes ...