in a number of games and sports, a ball that is out of bounds or stopped and out of play or declared to be out of play
After a dead ball, the ball becomes alive again when the pitcher stands on the pitcher's plate ready to pitch, the batter, catcher and umpire are ready, and the umpire calls or signals "Play."
also dead-ball , adj.
As soon as a rover touches the starting stake it becomes a dead ball and must be removed from the field.
If the ball hits the net during service, it is counted a dead ball and loses the server one of his trials.
The "live ball" is the next to play, and the "dead ball" is the name given to the adversary's ball which has just played.