A trick play in American football, the hook and lateral results in big yardage when properly run. The name is a play on firemen's "Hook & Ladder", but the play does in fact have both a hook and a lateral in it.
The first part of the play, the hook, requires a receiver to sprint out straight ahead and then immediately turn around to receive a pass from the quarterback. This type of route is called a button hook, and is designed to pick up specific yardage without any YAC (as the defender, who is probably a few steps back, will immediately move in to tackle the receiver ).
That's where the lateral comes in. At the same time the receiver is running this route, a secondary receiver or a running back trails the play at full speed, running to the outside of where the ball will be. If the timing is right, the secondary man is a few steps behind just as the receiver is getting clocked. The receiver, however, laterals the ball back to the secondary man, who is already in full stride. Thus, the defense is moving towards a useless stationary target, while the man with the ball is streaking towards the end zone.
The hook and lateral works very well against man-to-man defenses, especially those that play soft to prevent big plays. It has about a 0% chance against bump-and-run coverage. Variations of the play have more than one trailing player to provide upfield blocking.