How to Write 泗 (sì) — Meaning “Si (river name); mucus”

Imagine a river (氵) that is named after the number four (四), so the Si River flows with four streams. Or, for the mucus meaning, picture a person crying with four streams of tears and snot running down their face—this connects 涕泗 (tears and mucus) to the character.

The key is to write the left radical 氵 as three dots: the first two close together and the third a short diagonal stroke. The right part 四 must be written with the box first (outer stroke), then the left and right verticals inside, and finally the bottom horizontal—do not forget the two inner strokes that make it look like a window.

泗 (sì) means a river name or mucus and contains the water radical plus 四. 㳄 (xián) is a very rare character meaning "saliva" or "drool" and has a different right component (like 欠). 汊 (chà) means a branch of a river, and its right side is 叉 (fork), so it visually shows a water fork, while 泗 has no forking structure.

泗 is most commonly seen in place names like 泗水 (Sishui, a county in Shandong) or historical terms like 泗州 (an ancient prefecture). In literature, it appears in the word 涕泗 (tì sì), meaning "tears and mucus," often describing heavy crying. Outside of these, the character is very rare and not used in everyday conversation.

Common words containing 泗 include: 泗水 (sì shuǐ) — Sishui (river or county name); 涕泗 (tì sì) — tears and mucus; 泗州 (sì zhōu) — Sizhou (an ancient prefecture).