An outlet in the wall of a building or a parapet wall for drainage of water from a flat roof.
Merriam-Webster Online Dictionary
scupper (noun)1.
an opening cut through the bulwarks of a ship so that water falling on deck may flow overboard
2.
an opening in the wall of a building through which water can drain from a floor or flat roof
transitive verb
British to defeat or put an end to - do in
scupper (Wikipedia)
A scupper is an opening in the side walls of an open-air structure, for purposes of draining water. They are usually placed at or near ground level, and allow rain or liquids to flow off the side of the open-air structure, instead of pooling within the walls.
There are two main kinds of scuppers:
- Ships have scuppers at deck level, to allow for ocean or rainwater drain off.
- Buildings with railed rooftops can construct scuppers to let rainwater drain off, instead of pooling within the railing of the roof. Scuppers can also be placed in a parapet, for the same purpose.