blowback

noun5

1. •
   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.

   • The Israeli UZI submachine gun, one the most easily recognized examples of a blowback firearm, is well known for its simplicity, ease of manufacture, low maintenance, and utter reliability. — 2012
2. •
   (figurative) An unintended adverse result, especially of covert political action.

   • It is a story about blowback from Sunni Islamist extremists who went to Syria from various Arab countries and were allowed to assemble there in the aftermath of the U.S.-led invasion of Iraq in 2003. — 2008
3. •
   (slang) The act of shotgunning (inhaling from a pipe etc. and exhaling into another smoker's mouth).

   • Paranoid I was being ripped off, I 'tested' the potency of the skunk on a wasp by trapping it under a glass, and giving it a blowback. — 2012
4. •
   On a steam locomotive, the reversal of exhaust gases when the regulator is closed without using the blower.
5. •
   Synonym of backscatter.