counterintelligence
Americannoun
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the activity of an intelligence service employed in thwarting the efforts of an enemy's intelligence agents to gather information or commit sabotage. CI
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an organization engaged in counterintelligence. CI
noun
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activities designed to frustrate enemy espionage
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intelligence collected about enemy espionage
Etymology
Origin of counterintelligence
First recorded in 1935–40; counter- + intelligence
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
It calls for a mandatory registration system for foreign agents -- such as individuals and corporations lobbying within Japan on behalf of other governments -- as part of counterintelligence measures.
From Barron's • Feb. 27, 2026
The verdict marked the Justice Department’s first conviction on AI-related economic espionage charges, according to a statement from Roman Rozhavsky, assistant director of the FBI’s counterintelligence and espionage division.
From Los Angeles Times • Jan. 30, 2026
He married his first wife, fellow CIA agent Nancy Segebarth, in 1969, before being sent to Turkey as a counterintelligence officer to recruit foreign agents.
From BBC • Jan. 6, 2026
“Fidel Castro’s security detail had 10,000 officers and its own counterintelligence unit.”
From The Wall Street Journal • Jan. 6, 2026
He had been on the New York Committee for Detecting and Defeating Conspiracies along with John Jay, president of the Continental Congress and Washington’s chief of counterintelligence.
From "George Washington, Spymaster" by Thomas B. Allen
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
