What is the meaning of Out_of_bounds?

Where one is prohibited to enter.

Beyond the bounds of civility, morality, or normality.

Outside the area of play; beyond the sideline of a playing field or court.

A sideline marking the edge of a playing field or court.

An instance of a player or the ball going out of bounds.

Ground that one is not permitted to enter, or that is outside the permitted playing area.

Source: wiktionary.org