blow-back

Noun

blowback (countable and uncountable, plural blowbacks)

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, Robert E. Walker, Cartridges and Firearm Identification, CRC Press, →ISBN, page 24
2. (figuratively) An unintended adverse result, especially of covert political action.
   • All of the other retired C.I.A. officers who appeared before the subcommittee today acknowledged that the problem of the “domestic blowback” of agency propaganda had been a genuine problem, out most of them dismissed the mounting concern over C.I.A.'s past employment of American journalists as...1977 December 28, John M. Crewdson, “Colby Acknowledges U.S. Press Picked Up Bogus C.I.A. Accounts”, in The New York Times, →ISSN

   Synonyms:

   fallout

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, Caitlin Moran, Moranthology, Random House, →ISBN, page 41
4. On a steam locomotive, the reversal of exhaust gases when the regulator is closed without using the blower.
   • The Boulogne stop lasted a few minutes, during which I was surprised to see no use was made of the blower. In this country, if you shut the regulator without the blower on, the odds are there will be a blowback.1961 February, ""Balmore"", “Driving and firing modern French steam locomotives”, in Trains Illustrated, page 109
5. Synonym of backscatter.

   Synonyms:

   backscatter