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

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counterintelligence British  

/ ˌkaʊntərɪnˈtɛlɪdʒəns /

noun

1. activities designed to frustrate enemy espionage

2. intelligence collected about enemy espionage

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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.

Example Sentences

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 official had been under military counterintelligence surveillance for an extended period as a case was built against him, said special-services spokesman Jacek Dobrzynski.

From The Wall Street Journal • Feb. 3, 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

The man appeared in court this week and was detained without bail while a pre-trial investigation was being conducted by the SBU with support from counterintelligence units.

From BBC • Oct. 29, 2025

By 1951, Harvey had managed to scramble all the way to the top of the CIA's hierarchy, becoming the head of counterintelligence in just four years.

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