1
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
Relevance
Antonyms & Near Antonyms
as in spy
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
as in underground
Related Words
Dissimilar Words
Example Sentences
Examples are automatically compiled from online sources to
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Recent Examples of undercover
Billal Rahman, MSNBC Newsweek, 21 Oct. 2025
The ethics complaint alleges that if Homan received $50,000 from undercover FBI agents, it should have been reported on his financial disclosure forms.
—Avi Asher-Schapiro, ProPublica, 21 Oct. 2025
Time, 13 Aug. 2025
Meanwhile, the police send in state trooper Billy Costigan (DiCaprio) undercover to infiltrate Costello’s crime organization.
—Erik Kain, Forbes.com, 1 Aug. 2025
See All Example Sentences for undercover
Noun
Federal immigration authorities have deported a Nicaraguan national following an undercover child-exploitation investigation, according to a senior government official.
—Billal Rahman, MSNBC Newsweek, 21 Oct. 2025
The ethics complaint alleges that if Homan received $50,000 from undercover FBI agents, it should have been reported on his financial disclosure forms.
—Avi Asher-Schapiro, ProPublica, 21 Oct. 2025
Adverb
He is aided by Yasir Abbas, a weapons specialist; Raghuveer Singh, a sniper who served in Kashmir and Tawang; Uday Bhan, an explosives expert; and Sukhbir Singh, an Indian agent undercover in Pakistan posing as a Karachi stockbroker.
—Time, 13 Aug. 2025
Meanwhile, the police send in state trooper Billy Costigan (DiCaprio) undercover to infiltrate Costello’s crime organization.
—Erik Kain, Forbes.com, 1 Aug. 2025
See All Example Sentences for undercover
Recent Examples of Synonyms for undercover
Adjective
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Duplicity, directed by Tony Gilroy, follows two corporate spies, Claire (Roberts) and Ray (Owen), who become embroiled in a clandestine love affair.—
Carly Thomas,
HollywoodReporter,
14 Oct. 2025
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There’s a clandestine quality to it all.—
Roxana Hadadi,
Vulture,
14 Oct. 2025
Adjective
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The Institute for the Study of War (ISW) said on Friday the incident and the recent air incursion linked to Moscow show Kremlin plans for covert and overt attacks against Europe to prepare for a possible NATO-Russia war.—
Brendan Cole,
MSNBC Newsweek,
25 Oct. 2025
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The device is intended for intelligent underwater detection, real-time environmental monitoring, and potentially covert reconnaissance missions worldwide.—
Bojan Stojkovski,
Interesting Engineering,
25 Oct. 2025
Noun
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The Mark is a spy flick centered on Eden (Alba), an enigmatic spy on a covert and dangerous mission.—
Matt Grobar,
Deadline,
20 Oct. 2025
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The 57-year-old son of a schoolteacher, Munir ran Pakistan’s powerful Inter-Services Intelligence (ISI) spy agency before becoming top general in 2022.—
Sophia Saifi,
CNN Money,
18 Oct. 2025
Adverb
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The Tunnels story is that Chinese immigrants built a network of tunnels under the city because they were forced to live underground; the tunnels were then used by gangsters and bootleggers, including Al Capone.—
JSTOR Daily,
JSTOR Daily,
20 Oct. 2025
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Then a rental company pointed him to a seven-story chalet built into the side of a mountain in Deer Valley, with five of the floors underground.—
Abby Montanez,
Robb Report,
19 Oct. 2025
Adjective
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Get Ready: Katy Perry Has Released a Sneak Peek of Her New Song And the internet has receipts.—
Mehera Bonner,
Marie Claire,
15 Mar. 2017
Adjective
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My feeling is that the King will find suitable accommodation and the whole deal will be kept secret.—
Christina Dugan Ramirez , Ashley Papa,
FOXNews.com,
23 Oct. 2025
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The crime drama, based on Carl Weber’s bestselling book series of the same name, follows the wealthy and powerful Duncan family, who run the upscale Duncan Motors car dealership in New York as a front for their secret criminal empire.—
Samantha Stutsman,
PEOPLE,
23 Oct. 2025
Noun
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Only weeks later, on September 11, al-Qaeda operatives hijacked four passenger planes and carried out the deadliest terrorist attack in modern history, killing nearly 3,000 people.—
Big Think,
Big Think,
20 Oct. 2025
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The Gardaí believe that the smuggling attempt was arranged and co-financed by the Kinahans, Colombia’s Clan del Golfo, and Hezbollah operatives based in Venezuela.—
Ed Caesar,
New Yorker,
20 Oct. 2025
Adverb
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Pavlick allegedly placed the camera under the toilet seat and surreptitiously videotaped dozens of adults and children, police said, KCRG reports.—
KC Baker,
PEOPLE,
21 Oct. 2025
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Robert surreptitiously attains Alfred’s workbook/diary, where many secrets may exist.—
Kirk Honeycutt,
HollywoodReporter,
20 Oct. 2025
Cite this Entry
“Undercover.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/undercover. Accessed 26 Oct. 2025.
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