Origin

This character combines stone (石) on the left, which identifies the material, with a sound component (楚) on the right that hints at pronunciation. The left side makes sense because a foundation stone is literally made of rock or stone. The right component provides a phonetic clue to how the character should be pronounced, rather than contributing a separate meaning. Together, these parts create a character that points to the actual stones used to support and stabilize the base of structures.