一切經音義 21.257

21.257

從廣（從紫容反孟康注史記曰南北為從東西為橫橫即廣也字正體從木作有從糸作者皆俗通用也）。

Length and width (length [從]: fanqie 紫 + 容; Meng Kang's commentary on the Shiji states that north-to-south is 從 [length] and east-to-west is 橫 [breadth]; 橫 is width; the proper standard character is written with the wood radical; writing it with the silk radical is popular usage).