Scuttle: To sink a ship - good if you're the sinker, bad if you're the sinkee.
Forecastle: Below deck bow sleeping quarters... don't let the word 'castle' fool you - it's cramped.
Dredgie: Ghost or ghosts of pirates dead by betrayal - A.K.A. guys you don't want to mess with.
Black Jack: Large drinking cup made of leather and stiffened with tar - or one of the ways to earn some extra booty in the game!