Chou Collection, Upper Volume Radical: Mouth (kǒu) Ku Kangxi strokes: 20 Page 214, Entry 04 Pronounced ku. According to the Explaining Graphs and Analyzing Characters (Shuowen Jiezi), it refers to an urgent and extreme notification. Additionally, according to the Records of the Grand Historian (Shiji), Records of the Five Emperors, Emperor Ku of Gaoxin was the great-grandson of the Yellow Emperor. According to the Collection of Rhymes (Jiyun), it is also written in a variant form (ku). According to the Records of the Grand Historian (Shiji), Table of the Three Generations, Emperor Ku was the great-grandson of the Yellow Emperor.