An opening cut through the waterway and bulwarks of a ship, so that water falling on deck may flow overboard; -- called also scupper hole.
- Nautical An opening in the side of a ship at deck level to allow water to run off.
- An opening for draining off water, as from a floor or the roof of a building.
- Chiefly British To overwhelm or massacre.
- To ruin or destroy: "The world oil glut combined with disastrous federal energy policies to scupper Alberta's economy” ( Christian Science Monitor).