scupper verb [T] (SPOIL) to cause something such as a plan or an opportunity to fail: Arriving late for the interview scuppered my chances of getting the job.

A scupper is an opening in the side walls of a vessel or an open-air structure, which allows water to drain instead of pooling within the bulwark or gunwales of a vessel, or within the curbing or walls of a building.

scupper /ˈskʌpə/ n a drain or spout allowing water on the deck of a vessel to flow overboard