Kanji for Water — 水

水 is read mizu on its own and sui in compounds. It means water — and in Japanese, specifically cool water: hot water gets its own word, お湯 (oyu), which is why asking for 水 at a restaurant brings you a cold glass.

The four strokes draw a stream with eddies breaking off on both sides. Squeezed onto the left of another character it becomes 氵, the three-drop radical, and once you spot it you can guess half the vocabulary in a dictionary: 海 (sea), river 河, 泳 (swim), 洗 (wash).

水 is one of the five classical elements and the third day of the week, 水曜日 (suiyōbi), Wednesday. It also carries a nice idiom: 水に流す (mizu ni nagasu), “to let it flow away with the water”, means to forgive and forget an old quarrel.