Origin of blowbackblow + back (): in older sense of an explosion, expulsion of gas, and the like , as from a damaged gun or backfiring engine
- The backpressure in an internal-combustion engine or a boiler.
- Powder residue that is released upon automatic ejection of a spent cartridge or shell from a firearm.
- Negative repercussions affecting a country whose government has undertaken a usually clandestine intelligence operation in another country.
- (firearms) 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.
- An unintended adverse result, especially of a political action.
- (slang) The act of shotgunning (inhaling from a pipe etc. and exhaling into another smoker's mouth).