水道,河道
Watercourse \Wa"ter*course`\, n. (Shipbuilding) One of the holes in floor or other plates to permit water to flow through.
watercourse n 1: natural or artificial channel through which water flows 2: a natural body of running water flowing on or under the earth [syn: {stream}] 3: a conduit through which water flows [syn: {waterway}]