blowback

noun

1. firearmsA 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.

2. An unintended adverse result, especially of covert political action.

3. slangThe act of shotgunning (inhaling from a pipe etc. and exhaling into another smoker's mouth).

4. rail transportOn a steam locomotive, the reversal of exhaust gases when the regulator is closed without using the blower.

5. The backward escape of gases and unburned gunpowder after a gun is fired

   Similar: backfire

6. Misinformation resulting from the recirculation into the source country of disinformation previously planted abroad by that country's intelligence service

7. Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gases created by the ignition of the propellant charge.

   “In most actions that use blowback operation, the breech is not locked mechanically at the time of firing: the inertia of the bolt and recoil spring(s), relative to the weight of the bullet, delays opening of the breech until the bullet has left the barrel”

Synonym of backscatter.