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counterintelligence

American  
[koun-ter-in-tel-i-juhns] / ˌkaʊn tər ɪnˈtɛl ɪ dʒəns /

noun

  1. the activity of an intelligence service employed in thwarting the efforts of an enemy's intelligence agents to gather information or commit sabotage. CI

  2. an organization engaged in counterintelligence. CI


counterintelligence British  
/ ˌkaʊntərɪnˈtɛlɪdʒəns /

noun

  1. activities designed to frustrate enemy espionage

  2. intelligence collected about enemy espionage

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of counterintelligence

First recorded in 1935–40; counter- + intelligence

Explanation

Information and activity that helps to expose or eliminate spying or terrorist threats is counterintelligence. One of the things the CIA is responsible for is counterintelligence. Governments spy on each other, and the action of spying is called intelligence or espionage. When a country works to oppose or uncover spying, it's counterintelligence, or counterespionage. In the United States, both the CIA and the FBI have counterintelligence units. The word has been used since 1940, from counter, "against," and intelligence, from the Latin intelligentia, "power of discerning." The sense of intelligence as "secret information from spies" dates from the 16th century.

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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.

Under the previous Mexican administration, the government conducted strong counterintelligence that tracked U.S. law enforcement efforts across the country, said one person familiar with the operations.

From Los Angeles Times • Apr. 22, 2026

The number of FBI employees working in counterterrorism and counterintelligence continues to fall.

From Slate • Apr. 21, 2026

Rodriguez also replaced the head of the presidential guard, who leads the feared counterintelligence unit, and named a new economic czar.

From Barron's • Jan. 12, 2026

“Fidel Castro’s security detail had 10,000 officers and its own counterintelligence unit.”

From The Wall Street Journal • Jan. 6, 2026

The CIA's counterintelligence chief retired in the late 1980s, but when the Wall fell, he rejoined the Agency to take care of some unfinished business.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau

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