wasteweir ['weistwiә(r)]
n.
退水堰,弃水堰
wasteweir[ noun ]
a channel that carries excess water over or around a dam or other obstruction
<noun.artifact>
Wasteweir \Waste"weir`\, n.
An overfall, or weir, for the escape, or overflow, of
superfluous water from a canal, reservoir, pond, or the like.