UNDERCOVER Synonyms: 96 Similar and Opposite Words

undercover 1 of 3

adjective

ˌən-dər-ˈkə-vər

Definition of undercover

as in clandestine

undertaken or done so as to escape being observed or known by others an undercover operation to infiltrate the terrorist organization

Synonyms & Similar Words

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Antonyms & Near Antonyms

as in covert

working on missions in which one's objectives, activities, or true identity are not publicly revealed for months she's been an undercover agent pretending to be a drug dealer

Synonyms & Similar Words

Antonyms & Near Antonyms

overt

undercover

2 of 3

a person who tries secretly to obtain information for one country in the territory of another usually unfriendly country within the city was a well-organized fifth column, and these undercovers would make themselves known as soon as the invading forces breached the city limits

Synonyms & Similar Words

undercover

3 of 3

adverb

as in underground

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Dissimilar Words

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of undercover

Adjective

The movie follows Brian, an undercover Los Angeles police officer investigating a series of truck hijackings. — Lily Brown, PEOPLE, 24 Aug. 2026 Creamer’s group then sued O’Keefe and Maass over the video and their means of achieving the undercover clips. — Molly Parks, The Washington Examiner, 22 Aug. 2026

Noun

The Agency‘s second season will continue following Martian, a CIA agent living undercover in his own life. — Rosy Cordero, Deadline, 19 May 2026 Meanwhile, Chee goes further undercover. — Jordan Hoffman, Entertainment Weekly, 16 Mar. 2026 See All Example Sentences for undercover

Recent Examples of Synonyms for undercover

Adjective

The clandestine manner in which LG monitors were installing ad-pushing software onto third-party devices, however, remains seriously concerning.

— Scharon Harding, ArsTechnica, 24 Aug. 2026
The clandestine transits have changed the game for the Middle Eastern oil industry.

— David Goldman, CNN Money, 22 Aug. 2026

Definition of clandestine

Adjective

Psyops can be overt or covert, but they’re designed with a clear objective, said Jan Goldman, a professor of intelligence and security studies at The Citadel who has also worked on psyops.

— Harmeet Kaur, CNN Money, 27 Aug. 2026
In a recent presentation, OpenAI researchers described how AI agents used a covert message board to plan their next moves.

— Alex Heath, Time, 26 Aug. 2026

Definition of covert

Noun

Yet the Department of Military Counterintelligence—formally responsible for detecting foreign spies within the armed forces—has also been involved in many cases, reflecting the growing dependence of Russian industries on military contracts.

— Andrei Soldatov, Foreign Affairs, 31 Aug. 2026
The Bourne Identity Teens who enjoy action movies and spy capers will be all about the first film in the Bourne movie series, which came out in 2002.

— Kara Nesvig, Parents, 29 Aug. 2026

Definition of spy

Adverb

It was previously listed as a potential site for the National Museum of the American Latino in 2022, but was scratched over concerns that the small exhibition space could only be expanded underground.

— News Desk, Artforum, 24 Aug. 2026
Video shows the group, wearing overalls, pulling themselves out from underground and running away.

— Amethyst Martinez, USA Today, 24 Aug. 2026

Definition of underground

Adjective

Some are worried about the legal implications of handling such large quantities of previously private game builds as well.

— Kyle Orland, ArsTechnica, 30 Aug. 2026
In the village of Bilbasovka in eastern Ukraine, a 13-year-old child and an adult died after Russian troops dropped bombs on private houses Sunday, according to local official Vadim Lyakh.

— ABC News, ABC News, 30 Aug. 2026

Definition of private

Noun

Strategy and comms chief Nick Rathod, a seasoned political operative, served as Deputy Director in the Obama White House and a Special Assistant to the President.

— Jill Goldsmith, Deadline, 21 Aug. 2026
The complaint alleges that Bowie, who converted to Islam five years ago and became radicalized online, spent a month communicating with an ISIS facilitator who was actually an undercover operative working with the FBI.

— Adam England, PEOPLE, 21 Aug. 2026

Definition of operative

Adverb

Right now, there are no indications exploits are being used to install anything other than Monero miners, which surreptitiously harness a Mac’s resources to perform mathematical operations that generate the cryptocurrency for the attacker.

— Dan Goodin, ArsTechnica, 14 Aug. 2026
That's not the first time a president surreptitiously switched planes.

— Phaedra Trethan, USA Today, 11 Aug. 2026

Definition of surreptitiously

Cite this Entry

Style

“Undercover.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/undercover. Accessed 2 Sep. 2026.

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Synonyms of undercover

adjective

noun

adverb

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