Cornerback/ˈkɔːrnərbæk/ Definition 1 of 1Pro Tip 1/3Sport Specific Used mainly in discussions about American or Canadian football, not other sports. His dream is to become a great cornerback like his idol. Pro Tip 2/3Defensive Role Emphasizes the role of preventing the opposite team's success, not scoring points. The cornerback rushed in to block the pass. Pro Tip 3/3Game Jargon Commonly used among football fans and players, but unfamiliar to those outside the sport. They debated who the best cornerback was after the game.