Definition of sluice:
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 of flood gate; hence, an opening or channel through which anything flows; a source of supply
"each sluice of affluent fortune opened soon. -Harte."
to emit by, or as by, flood gates. [R.] Milton; to wet copiously, as by opening a sluice; as, to sluice meadows. Howitt