The drain, in
pinball terms, is a hole in the
playfield that usually ends the turn when the pinball falls into it. It is located at the bottom of the playfield in such a way that the pinball must pass the
flippers or go through the
outlanes to reach it. The drain is sometimes (rarely these days) called the
outhole.
Drain is also the term used for the event of losing a ball into the hole.
Quite possibly, the fundamental goal of the game of pinball is keeping the pinball out of the drain for as long as possible.