水槽
shuǐ cáo · HSK 7
sink
🚰 水槽 = water (水) + trough/tank (槽) = the water trough you wash in: a sink
槽 on its own is a trough or tank; bolt water (水) in front and you get the basin water pools in. Note shuǐ is third tone (dipping) and cáo is second tone (rising).
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.
槽 — wood radical 木 + 曹 (cáo, phonetic)
槽 is a phono-semantic compound. The wood radical 木 signals the meaning—originally a wooden trough or feeding basin for animals. The component 曹 supplies the sound 'cáo'. From 'trough' it extended to any long hollow channel or groove, as in 河槽 (riverbed) or 牙槽 (tooth socket).