Chou Collection, Middle Volume. Radical: Scholar (shì). Kangxi stroke count: 9. Page 243, Entry 05.
Broad Rhymes (Guangyun): Pronounced zhu (falling tone). Collected Rhymes (Jiyun): Pronounced zhu (falling tone). Denotes music. Also used as a loan word for standing upright. Found in Rhyme Treasure (Yunbao). The Correct Explanation of Characters (Zhengzitong) states it is a misspelling of the character meaning how or why (qi).
Explanation in the Explaining Graphs and Analyzing Characters (Shuowen Jiezi): Music established and displayed upward. The character structure consists of the sprout (che) radical and the bean (dou) radical. Categorizing it under the scholar (shi) radical is incorrect.