Baulk is the British spelling of balk. As a verb it means to stop short and refuse to go on: a horse baulks at a jump; a person baulks at a price, or at telling a lie. You can also baulk someone, meaning you get in their way and stop them. As a noun it can be a thick beam of wood, or, in snooker and British billiards, the marked area at one end of the table (almost always spelled baulk there). Americans write balk, and in baseball the pitcher’s illegal move is nearly always spelled balk even in Britain. Many speakers drop the l-sound: it often sounds like “bork.”