chhù-āu-kau厝後溝

ditch for draining water at the back of a house

ditch for draining water at the back of a house with back to a mountain; mountain side behind a house with back to a mountain

by extension

English Wiktionary, “厝後溝” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E5%8E%9D%E5%BE%8C%E6%BA%9D · confidence: Medium (Wiktionary)