Definition: A feeder is one of the players in a training drill, who is performing the simpler part of the drill.
The act of performing the simpler part of the drill is called feeding the ball.
A typical example of this would be where the feeder blocks the ball to the forehand corner and middle of the table in turn, while his training partner loops the ball to the feeder’s forehand block. The feeder is said to be feeding the ball to the looper.
When performing multiball, the person who is hitting the balls from the container at the side of the table is also called the feeder.