Source : Webster's Revised Unabridged Dictionary (1913)

Waterway \Wa"ter*way`\, n. (Naut.)
   Heavy plank or timber extending fore and aft the whole length
   of a vessel's deck at the line of junction with the sides,
   forming a channel to the scuppers, which are cut through it.
   In iron vessels the waterway is variously constructed.

Source : WordNet®

waterway
     n 1: a navigable body of water
     2: a conduit through which water flows [syn: {watercourse}]