v obstruct; stymie: We were planning on having a party but then my folks arrived home early and scuppered that. The term derives from seafaring, where the scupper is a drain designed to allow water to flow overboard from the deck. To be scuppered is to be hit by a wave large enough to knock you into this drain. Of course, it could also derive from the more obvious seafaring source where scuppering something is sinking it, but hey. I make a lot of these up on the spot.