n. A body of water held in check by a flood-gate; a stream of water issuing through a flood-gate.n. A gate or other contrivance by which the flow of water in a waterway is controlled; a flood-gate; also, an artificial passage or channel into which water is allowed to enter by such a gate; a sluiceway; hence, any artificial channel for running water: as, a mill -sluice.n. In mining, a trough made of boards, used for separating gold from the gravel and sand in which it occurs.n. In steam-engines, the injection-valve by which the water of condensation is introduced into the condenser.n. A tubulure or pipe through which water is directed at will.To open a flood-gate or sluice upon; let a copious flow of water on or in: as, to sluice a meadow.To draw out or off, as water, by a sluice: as, to sluice the water into the corn-fields or to a mill.To wet or lave abundantly.To scour out or cleanse by means of sluices: as, to sluice a harbor.To let out as by a sluice; cause to gush out.n. Same as flume, 4.In lumbering: Same as flume, 2.To float (logs) through the sluiceway of a splash-dam. Same as splash, 5.To injure (as a team of horses or their driver) by the down-rush of a load of logs due to the breaking of the hawser used to control its descent over a steep slope.