小便
しょうべん · shouben · JLPT N2 · noun
urine
🚽 小便 = 小 (small) + 便 (excrement/convenience): the small one, casual word for urine
便 means excrement or convenience. 大便 is the big one (feces), so 小便 is the small one. It is a casual, slightly crude term, so use it mainly with friends.
小 — three small strokes around a central vertical
小 is a pictograph originally showing three tiny dots or specks, suggesting small particles or grains. Over time the dots became stylized strokes flanking a central line. The core meaning 'small' has stayed remarkably stable from oracle bone script to today.
便 — person 亻 + change 更
A semantic compound: 亻(person) beside 更 (to change/replace). The original sense was a person making things easier or more convenient by adjusting them. From 'convenient' it extended to 'then/thereupon' (biàn) and to bodily 'discharge' (as in 大便).