1 The normal reaction of powder gasses directly rearward against the bolt or breechblock at the time of explosion and sometimes used to operate the action. 2 Rearward escape of powder or primer gasses from the chamber around the bolt or breechblock caused by a split or fractured cartridge case or a punctured primer.

An operation system in self-loading firearms in which the slide or breechblock is driven to the rear by direct gas pressure on the cartridge case head.

A semi or fully automatic action where the bolt does not lock. The breech is held closed by the weight of the bolt and the pressure provided by the recoil spring. Most often found in small pistols and in submachine guns like the Uzi and MP5.

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

A term used in foreign policy/intelligence circles referring to the unintended consequences of foreign policy/military actions.

Blowback is a term now broadly used in espionage to describe the unintended consequences of covert operations. Blowback typically appears as a surprise, apparently random and without cause, because the public generally is unaware of secret operations that caused it.

Blowback is the sixth album of Bristol, England rapper/producer Tricky, released in 2001. Blowback contains a number of collaborations like Nearly God did, but the sound is much brighter and more relaxed. Tricky himself says that he wants to get airplay with this album, while most of his older albums were made to stay off the radio.

the backward escape of unburned gunpowder after a shot.

UK: Blowing the smoke backwards through a joint into the mouth of another smoker

the retaliation for underhanded activity where that activity was kept secret from the people, so that the retaliation appears without motivation.

a powerful three-hander about race, love, despondency, accountability and responsibility

The number of pounds per square inch of pressure drop in a boiler from the point where the safety valve pops to the point where the safety valve reseats.

To reverse flow air, steam, or fluid through the medium to effect solids removal. Sometimes referred to as backwash.

The enlargement of a microfilm image to viewing size.