noun
culvert; underground drain; conduit
Refers to a covered channel or pipe that carries water underground, often used in civil engineering or drainage contexts. Contrasts with 明渠 (open ditch).
See also: 明渠
この道路の下には古い暗渠が通っている。
An old culvert runs under this road.
暗渠工事のため、通行止
The road will be closed due to culvert construction.
明渠 is an open ditch or channel, while 暗渠 is a covered underground conduit.
Compound of 暗 (dark, hidden) and 渠 (ditch, channel). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning of a covered waterway.