洪水
こうずい · kouzui · JLPT N1 · noun
flood
🌊 洪 (flood) + 水 (water): a flood is simply a great deal of water
洪 means vast or overwhelming, and 水 means water. Put together they name a flood, a huge rush of water over land.
水 — pictograph of flowing water
水 is a pictograph depicting a stream of flowing water, with the central line representing the main current and the side strokes showing splashing droplets or ripples. In oracle bone script it was drawn even more clearly as a wavy vertical line with branches. It retains its original meaning of 'water' and also serves as a radical, often appearing in the compressed form 氵.