from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The backpressure in an internal-combustion engine or a boiler.
- n. Powder residue that is released upon automatic ejection of a spent cartridge or shell from a firearm.
- n. The effect caused by recirculation into the source country of disinformation previously planted abroad by that country's intelligence service in an effort to mislead the government of another country.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. 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.
- n. An unintended adverse result, especially of a political action.
- n. The act of shotgunning (inhaling from a pipe etc. and exhaling into another smoker's mouth).
from the GNU version of the Collaborative International Dictionary of English
- n. the backward escape of unburned gunpowder after a shot.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the backward escape of gases and unburned gunpowder after a gun is fired
- n. misinformation resulting from the recirculation into the source country of disinformation previously planted abroad by that country's intelligence service
blow + back (Wiktionary)