Origin

The character 柱 combines the wood radical on the left, which shows this word refers to something wooden or made of wood, with the component 主 on the right, which serves as a sound hint for the pronunciation. The 木 radical makes perfect sense because pillars and posts are typically wooden structures that support buildings. By pairing a meaning component showing "wood" with a sound indicator, the character efficiently conveys both what the object is and hints at how to say it.