(topology, mathematical analysis, restricted to metric spaces) The set of all points in a metric space whose distance from a given point ("the open ball's center") is less than a given length ("the open ball's radius").

A form of handgun that fires projectiles of rubber of similar material, used mainly by law enforcement officers for riot control.

plural of flash-ball

(soccer) A forward pass played between opposition defenders.

(idiomatic) A person who is especially hard-working, high-achieving, ambitious, or active.

A method used to begin or resume play in basketball. Two opposing players attempt to gain control of the ball after it is tossed up into the air in between them by an official.

plural of rugby ball

(baseball) An instance where the batter is allowed to go directly to first base without the possibility of being put out, due to the opposing pitcher delivering four balls.

Alternative spelling of base on balls

Alternative form of through ball