You Collection, Lower Volume
Radical: Carriage (chē)
Shi; Kangxi strokes: 13; Page 1242
Pronounced shi
From the Expanded Dictionary of Sounds (Guangyun) and the Collected Rhymes (Jiyun), the pronunciation is shi.
From the Explaining Graphs and Analyzing Characters (Shuowen), it refers to the crossbar in front of a carriage.
From the Explanations of Names (Shiming), the crossbar (shi) signifies a pattern or rule (shi). It is where one leans forward to show respect.
From the History of the Later Han (Hou Hanshu), Biography of Zhang Zhan, it mentions leaning on the carriage crossbar.
Commentary: When riding in a carriage, one must stand upright; if there is someone to respect, one leans on the crossbar, which means to bow slightly. It is also commonly written as the variant form (shi).
From the Analects (Lunyu), to bow to those carrying population registers.