Wiktionary
afterbay
n. (context hydrology English) a stream, conduit, pond or reservoir, of a hydroelectric power plant at the outlet of the turbines.
Usage examples of "afterbay".
His hat had come off and gone spinning away down the afterbay wall, and his pompadour was broken into wet strands plastered across his forehead.
Lance in hand, he flew through the vast afterbays toward the central core.