Source : Webster's Revised Unabridged Dictionary (1913)

Watercourse \Wa"ter*course`\, n. (Shipbuilding)
   One of the holes in floor or other plates to permit water to
   flow through.

Source : WordNet®

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}]