defensive position in American and Canadian football, covering receivers, to defend against pass offenses and make tackles

A cornerback is a position on defense in American football. Corners can rush the passer, intercept balls, tackle, and deflect passes. Their main job is to stop the opponent's receivers from making a catch. Cornerbacks usually line up on the edges, or sides, of the defensive line opposite their opponent's receivers. In zone defense, corners are assigned to a specific area of the field, in which they cannot let anyone make a catch. In man defense, corners cover one player and try to stop them from catching a ball.

Oakland Raiders cornerback Nnamdi Asomugha covers Atlanta Falcons wide receiver Michael Jenkins on November 2, 2008 in a National Football League game.