Xu Collection, Upper Volume Radical: Metal (jīn) 鈕 Kangxi strokes: 12 Page 1298, Entry 23 Ancient script form. According to the Tang Rhyme (Tangyun), Collection of Rhymes (Jiyun), and Correct Rhymes (Zhengyun), the pronunciation is niu (rising tone). According to the Explaining Graphs and Analyzing Characters (Shuowen), it refers to the knob of a seal. According to the Correct Rhymes (Zhengyun), it also refers to the knob of a mirror or crossbow. According to the Correct Meaning Through Characters (Zhengzitong), any object used to hook or fasten something is called a niu. Also, in the Songs of Chu (Chuci), Nine Longings (Jiusi), it is written: Abandoning the knob and the pivot. The commentary states that the jade dipper, the knob, and the pivot are all things that are treasured. It is also a surname. According to the He Family Surname Garden (He Shi Xing Yuan), there was a person named Niu during the Eastern Jin dynasty, who was from Wuxing. Also, according to the Collection of Rhymes (Jiyun), the pronunciation is chou (rising tone). It is the same as the character for shackles, referring to wooden handcuffs.