Definition of the word blowback

The term "blowback" has its origins in the field of engineering and aerodynamics. In the early 20th century, it referred to the unintended backward motion of gases or particles that resulted from the forward motion of an object, such as a jet of air or steam escaping from a cylinder. In the 1950s and 1960s, the term "blowback" began to be used in the context of covert operations and espionage to describe the unintended consequences or "unforeseen fallout" of a covert action or espionage operation. For example, the CIA's involvement in the coup that overthrew the democratically-elected government of Iran in 1953 led to a backlash of anti-American sentiment and the 1979 Iranian Revolution, which was often referred to as a "blowback" reaction. Today, the term "blowback" is often used more broadly to refer to any unintended or unforeseen consequence of a particular action or policy.