世故
shì gù , shì gu · HSK 7
the ways of the world
🌍 世 (world) + 故 (affairs/reasons) = knowing how the world's affairs really work
故 — 古 (old) + 攵 (action/strike)
故 combines 古 'old' as the phonetic with 攵, a variant of 攴 meaning to strike or act. Originally it referred to a cause or reason behind an action. From this it extended to mean 'former, old, deceased' and 'therefore, hence' as a connector.