cornerback
n.a defensive player in American football who stands near the edge of the field. Their main job is to stop the other team's receivers from catching the ball.
n.a defensive back positioned near the sideline whose primary responsibility is to cover wide receivers and defend against passing plays. Typically requires high speed and agility to match the movements of offensive players.
“The cornerback intercepted the pass near the sideline.”
“The team's star cornerback was assigned to follow the opponent's best receiver across the entire field.”
“Elite defensive strategies often rely on a shutdown cornerback who can effectively neutralise a primary receiving threat without requiring constant safety help from the middle of the field.”
From corner + back.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.