adv. or adj. phr. 1. Outside of the boundary lines in a game; not on or inside the playing field. Bill thought he had scored a touchdown, but he had stepped out of bounds before he reached the goal line. 2. Outside of a circumscribed area for a certain kind of work, such as construction or military site. The principal told the students that the new gymnasium being built on the school grounds was out of bounds. The captain's cabin is out of bounds to the passengers on the ship.
Antonym: WITHIN BOUNDS. 3. Outside of safe or proper limits; not doing what is proper; breaking the rules of good behavior. John was out of bounds when he called Tom a liar in the meeting. His request for a 25% salary raise was totally out of bounds.