A sudden move is an abrupt, unexpected change in direction or action. The term can be broken down into four crossword solutions: LURCH (5 letters), LUNGE (5 letters), ZIG (3 letters), and START (5 letters). A LURCH is a sudden, jerky movement, while a LUNGE is a sudden forward thrust. Zigging is a sharp change of direction, while starting is the act of beginning something. All of these words describe a sudden move in some way.