A natural or artificial means for the removal of fluids from a given area by its draining away. / A system of drains. / A downward wind.

plural of drainage

(physics, meteorology) The gravity-induced downslope flow of relatively cold air. Winds thus produced are called gravity winds.

(hydrology) A topographic region in which all water drains to a common outlet; a watershed.

A conduit for the removal of water or waste water.

plural of drainage basin

(construction) the drainage condition in which consideration has been made during design for all loading deflections of the deck and additional roof slope has been provided to ensure drainage within 48 hours following rainfall during conditions conducive to drying.

(geomorphology) pattern formed by the streams, rivers, and lakes in a particular drainage basin

plural of drainage pipe

plural of drainage system