An artificial passage for water, fitted with a valve or gate, for example in a canal lock or a mill stream, for stopping or regulating the flow.
A water gate or floodgate.
Hence, an opening or channel through which anything flows; a source of supply.
The stream flowing through a floodgate.
A long box or trough through which water flows, used for washing auriferous earth.
An instance of wh-stranding ellipsis, or sluicing.