n. (Brit.)
25B6; verb
the captain decided to scupper the ship : SINK, scuttle, submerge, send to the bottom.
(informal) he denied trying to scupper the agreement : RUIN, wreck, destroy, sabotage, torpedo, spoil, mess up; informal screw up, foul up, put the kibosh on, banjax, do for; archaic bring to naught.