注 is built from the 氵 (water (left)) and 主 components.
It belongs to a phonetic family with 住, 駐, and 柱 — they share the 主 component and the reading チュウ.
A common word using 注 is 注意 (ちゅうい), meaning “caution, attention”.
Don't confuse it with 住, 往, 柱, and 駐.
