Curl

Schematic of a "curl" route or hook route. A curl route (also known as hook route in some Latin American countries) is a pattern followed by a receiver in American football, where the receiver seems to be running a straight pattern, but after several steps or yards will stop and turn, looking for a pass. This usually works best when the cornerback or safety continues to run to cover the straight path and can not be stopped or turned quickly to defend the pass.

The curl route is often used by the West Coast offensive scheme, which favors fast and accurate passes.

wiki