"Auto sear" means a device, other than a trigger activator, designed for use in converting a semi-automatic firearm to shoot automatically more than one shot, without manual reloading, by a single function of the trigger.
"Trigger activator" means a device designed to allow a semi-automatic firearm to shoot more than one shot with a single pull of the trigger by harnessing the recoil energy of any semi-automatic firearm to which it is affixed so that the trigger resets and continues firing without additional physical manipulation of the trigger by the shooter.
Va. Code § 18.2-308.5:1