drainage

n. emptying of liquid, channeling; sewage, waste water

Drainage is the natural or artificial removal of surface and sub-surface water from a given area. Many agricultural soils need drainage to improve production or to manage water supplies.
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Drainage /drain·age/ systematic withdrawal of fluids and discharges from a wound, sore, or cavity. capillary drainage that effected by strands of [more]Drainage - Community and Resources

Noun
1. emptying accomplished by draining
(synonym) drain
(hypernym) emptying, voidance, evacuation
(derivation) drain, run out

n. drainage, drain, gutter