-nij, -nēj noun
( -s )
1.
a. : the act or an instance of draining
by this drainage of colonial wealth the empire financed its costly wars
drainage of the marshy lands was completed in a short time
b. : draining : a gradual flowing off or dropping down
complained of drainage of rain water into the cellar
gold drainage and gold hoarding … were feared — F.L.Paxson
also : something that is drained off
this lake receives the drainage of many mountain streams
c. chiefly Britain : sewage ; also : the sewage system of a building
2. : the manner in which the waters of a country pass off (as by streams and rivers)
subsurface drainage
3.
a. : the removal of excess water from land by means of surface or subsurface conduits ; also : a system of such conduits
b. : aerial drainage
4.
a. : area or district drained (as by a river)
b. or drainage system : the streams or other waterways by which a region is drained
5. : the act, process, or means of drawing off fluids from a cavity or wound by means of suction or gravity
6. : a process or means of release of internal conflicts or pent-up feelings (as hostility or guilt)