注
zhù · HSK 7
explanatory note
📝 氵water + 主 main = pour main idea into text; 主 also gives the zhù sound
注 started as water 氵being poured (主 supplies the zhù sound). A note pours extra meaning into a text, so 注 came to mean an explanatory annotation.
注 — water 氵 + master 主 (phonetic)
A semantic-phonetic compound: 氵 (water) gives the meaning of pouring or flowing, while 主 supplies the sound. The original sense was 'to pour water in,' which extended to 'concentrate, focus' (as in pouring attention) and 'to annotate' (pouring explanation into a text).