scupper

Scupper appeared in English in the fifteenth century. Its origin is disputed — it may come from Old French escopir (to spit out) or from a Scandinavian source related to the idea of scooping. A scupper is an opening in the ship's side at deck level that allows water to drain off the deck and overboard. Without scuppers, every wave that washes over the deck would add to the water on board until the ship became dangerously heavy.

The design is simple: a hole in the hull at deck level, sometimes fitted with a non-return valve (scupper valve) to prevent seawater from entering when the ship rolls and the scupper dips below the waterline. The scupper must be large enough to drain water quickly but not so large that it weakens the hull. On modern ships, scuppers are connected to drainpipes that direct water safely overboard.

The verb 'to scupper' — meaning to ruin, to sink, to put an end to — appeared in British English in the nineteenth century, probably from the idea of a ship being sunk through its scuppers. 'The plan was scuppered' means the plan was destroyed, as a ship is destroyed when water enters through blocked or damaged scuppers. The drain that saves the ship became a metaphor for the vulnerability that sinks it.

The word appears in the expression 'scuppered' (drunk), used in British and Australian English. The connection may be to the idea of someone listing (leaning) like a ship taking on water, or simply to the broader sense of being ruined. The drain, the sinking, the drunkenness, and the failure all share a single word.