blow·back /ˈbləʊbæk $ ˈbloʊ-/ noun [uncountableU]1 bad results of an action which were not intendedWe are now suffering the blowback of the terrible foreign policy choices made by the previous president.
2 the powder that is sent out when a gun is firedOther inconsistencies included the absence of fingerprints on the gun and of blowback material from the gun blast.