Moonball

A ball hit extremely high in the air, like a lob, but not with the same offensive or defensive motives that inspire, or force, a lob. A moonball is hit during a baseline rally with the intention of upsetting an opponent's pace and rhythm, to possibly precipitate an error or a weak return shot. Moonballs are often answered with return moonballs, that being a rather safe way of circumventing danger, and when that happens and perhaps continues, the whole affair seems to degenerate, and the gallery starts whistling.