Definition: The top half of a cue stick, from the cues joint, if it has one, to the tip.
Two-piece cues often have a shaft with greater flexibility than the butt half, to help the stick respond better to collision with the cue ball. A whippy shaft also keeps the cue tip on the balls surface longer, increasing spin with a minimal effort on the players part.
Examples:
Chandra had two interchangeable shafts for her cue, one with extra stiffness and one quite whippy for extra zing when called for in her game.

