Handguard in the context of "Forearm (firearm component)"

Pump action is a type of manual firearm action that is operated by moving a sliding handguard on the gun's forestock. After shooting a round, the sliding handguard is pulled rearward to eject any expended cartridge and typically to cock the hammer or striker, and then pushed forward to load a new cartridge into the chamber. Most pump-action firearms use an integral tubular magazine, although others use detachable box magazines. Pump-action mechanisms are typically found in shotguns, although they also may be found in rifles, grenade launchers, and other types of firearms. A firearm using this operating mechanism is colloquially referred to as a pumpgun.

Because the forend (handguard) is usually manipulated with the support hand, a pump-action firearm can fire additional shots much faster than a bolt-action and somewhat faster than a lever-action, as it does not require the trigger hand to be removed from the trigger while reloading. Also because the action is cycled in a linear fashion, it creates less torque that can tilt and throw the gun off aim when repeat-firing rapidly.