Jump Ball.

A method of putting the ball back into play at the beginning of a game or after a held ball, when players from opposing teams gain simultaneous possession of the ball and at this situations, the referee stops play. Two opponents face one another in one of the three restraining circles, and after the teams are realigned outside the circle until the ball is touched, the referee tosses the ball up between those two players, who attempt to tap it to a teammate.

Jump Hook.

A hook shot, taken while jumping, popular among big men because it is difficult to block.

Jumper.

A jump shot.

Jumping Circle.

A 4-foot circle inside the center circle. On a jump ball, each player must have at least one foot entirely inside the jumping circle.