scupper UK /ˈskʌpə/US /ˈskʌpɚ/noun 2verb 1forms 3 noun2 •A drainage hole on the deck of a ship. •A similar opening in a wall or parapet that allows water to drain from a roof. verb1 •(UK) To thwart or destroy, especially something belonging or pertaining to another.The bad media coverage scuppered his chances of being elected. formsscuppered · scuppering · scuppers