Dictionary.com
Thesaurus.com
Showing results for counterintelligence. Search instead for Increase+Intelligence.

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.

Keep Reading on Vocabulary.com

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.

“Drones are just more effective and cost less,” said Kovalskiy, who is part of a military counterintelligence division of the Security Service of Ukraine, or SBU.

From The Wall Street Journal • May 14, 2026

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

From Slate • Apr. 21, 2026

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

Following HERO'S arrest, they had stopped recruiting Soviet informers under orders from James Jesus Angleton, the secretive and paranoid CIA chief of counterintelligence.

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

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember "counterintelligence" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com