Any route run by an offensive receiver that ends with the player turning and heading back towards the quarterback. Comeback routes can be any length down the field, but the focus is always gaining separation from the defender before cutting quickly back towards the quarterback to receive the ball. A good quarterback will deliver the pass at the same time the receiver turns to come back, reducing the time for the defense to react.
The comeback route is a staple of any passing game. Like most pass routes, the comeback is designed to force the defense to respect one potential route in order to open up another. In the case of the comeback route, the receiver is making the defender respect a deep route, forcing the defender to commit to guarding deep. Once that defender commits, it leaves the comeback open. The route is not as effective as other routes at gaining yards after the catch because the receiver's momentum is in the wrong direction.