In American football

American football

American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

 a pass deflected, also known as a pass defended, a pass defensed, a pass knock down, or a pass break up, is an incomplete pass

Incomplete pass

An incomplete pass is a term in American football which means that a legal forward pass hits the ground before a player on either team gains possession. For example, if the quarterback throws the ball to one of his wide receivers, and the receiver either does not touch it or tries to catch it...

 that is caused by a defensive player. This is done by slapping or blocking the ball, and is an important statistic for determining a defensive back's effectiveness.

An interception is similar to a deflected pass, except the defender catches and gains possession of the football.