noun A type of action where the pressure from the fired cartridge blows a sliding mechanism backward to extract the fired cartridge, chamber another cartridge, and cock the hammer.
noun An unintended adverse result, especially of covert political action.
noun The act of shotgunning (inhaling from a pipe etc. and exhaling into another smoker's mouth).
noun On a steam locomotive, the reversal of exhaust gases when the regulator is closed without using the blower.