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.-hence, an opening or channel through which anything flows; a source of supply.-the stream flowing through a flood gate.-a long box or trough through which water flows, -- used for washing auriferous earth.-to emit by, or as by, flood gates.-to wet copiously, as by opening a sluice; as, to sluice meadows.-to wash with, or in, a stream of water running through a sluice; as, to sluice eart or gold dust in mining.