What does "squawk" mean in ATC communications?

In ATC communications, "squawk" refers specifically to the process of setting a transponder to a designated code provided by Air Traffic Control (ATC). This code is crucial for the identification of the aircraft on radar, allowing ATC to track its position and ensure safe separation from other aircraft. When a pilot is instructed to "squawk a certain code," it typically involves entering that numeric code into the aircraft's transponder, which broadcasts information about the aircraft to ATC radar systems.

Setting the transponder to the correct code enables the aircraft to be visually identified on radar displays. This identification is essential for maintaining flight safety and coordination among various aircraft in the controlled airspace. Thus, when pilots are told to squawk a specific code, they are directly responding to a request that enhances situational awareness for both the pilot and the air traffic controllers.