柱子
zhù zi · HSK 6
pillar
🏛️ 木 wood + 主 main = the main wooden beam, a pillar
The radical 木 tells you it is made of wood. 主 (zhǔ, master/main) gives both meaning and sound — the master support column. 子 is a common noun suffix.
子 — pictograph of a baby/child with arms out
子 began as a pictograph of a swaddled infant with a large head and outstretched arms, originally meaning 'baby' or 'child.' From there it broadened to 'son,' 'offspring,' and a respectful suffix for masters like 孔子 (Confucius). It also became one of the twelve earthly branches.