Touchline/ˈtʌtʃlaɪn/ Definition 1 of 2Pro Tip 1/3Sports Boundary The touchline is the boundary athletes must stay within during play. She dribbled the ball skillfully along the touchline. Pro Tip 2/3Game Restart When a ball crosses the touchline, the game is paused to restart play. The referee blew the whistle as the ball rolled over the touchline. Pro Tip 3/3Spatial Awareness Players must be aware of the touchline's location to effectively strategize. He glanced at the touchline to ensure he was not offside.