Sluice n.
1. An artifical passage for water, fitted with a valve or gate, as in a mill stream, for stopping or regulating the flow; also, a water gate or flood gate.
2. Hence, an opening or channel through which anything flows; a source of supply.
Each sluice of affluent fortune opened soon. --Harte.
This home familiarity . . . opens the sluices of sensibility. --I. Taylor.
3. The stream flowing through a flood gate.
4. Mining A long box or trough through which water flows, -- used for washing auriferous earth.
Sluice gate, the sliding gate of a sluice.