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
Larae Quy, Forbes.com, 23 June 2025
The Special Investigations Division’s Child Exploitation Prevention Unit conducted an undercover operation to combat online child exploitation, Boisvert said.
—Staff Report, Hartford Courant, 19 June 2025
Guy Lawson, Rolling Stone, 24 Mar. 2024
Back at the hospital Jack tells Brady that working undercover took a lot of courage.
—Jessica Radloff, Glamour, 8 Sep. 2023
See All Example Sentences for undercover
Noun
My greatest lesson about the importance of authentic leadership came from my first undercover assignment as an FBI agent.
—Larae Quy, Forbes.com, 23 June 2025
The Special Investigations Division’s Child Exploitation Prevention Unit conducted an undercover operation to combat online child exploitation, Boisvert said.
—Staff Report, Hartford Courant, 19 June 2025
Adverb
Blazer had been wearing a wire, working in tandem with an FBI undercover, ensnaring more than ten coaches in an elaborate plot that revealed corruption in the basketball programs at Louisville, Arizona, LSU, USC and other schools.
—Guy Lawson, Rolling Stone, 24 Mar. 2024
Back at the hospital Jack tells Brady that working undercover took a lot of courage.
—Jessica Radloff, Glamour, 8 Sep. 2023
See All Example Sentences for undercover
Recent Examples of Synonyms for undercover
Adjective
-
After paying private equity tycoon Jack McGinley $52 million in a clandestine off-market deal for the Georgian-style spread, which was designed by architect Don Nulty and built in 2009 for 9-1-1: Lone Star actor Rob Lowe, Levine and Prinsloo have put the place back on the market for $65 million.—
Wendy Bowman,
Robb Report,
10 July 2025
-
Built to listen for clandestine nuclear bomb blasts, the globe-spanning system detects low-frequency acoustic-gravity waves.—
Deni Ellis Béchard,
Scientific American,
9 July 2025
Adjective
-
Now, after Operation Midnight Hammer, arguably one of the most perfect covert military operations in U.S. history, who could argue? Even Trump’s most ardent critics had to give him credit.—
Sun Sentinel Editorial Board,
Sun Sentinel,
28 June 2025
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This deliberately allusive narrative style enables the author to elude the topic of Nazism—or at least to hint at it in a covert way, thus making the novel acceptable to a wide German audience at the time of its publication in 1968.—
Ombline Damy,
JSTOR Daily,
26 June 2025
Noun
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For those who don't know, Area 51 is a large, secretive military base in the remote Nevada desert where several exotic military aircraft have been developed and tested over the years, including the venerable U-2 spy plane way back when.—
Jim Clash,
Forbes.com,
6 July 2025
-
Israel’s spy service conducted elaborate sabotage operations on Iranian soil.—
Nabih Bulos
Foreign Correspondent,
Los Angeles Times,
5 July 2025
Adverb
-
The chemicals that leach up from deep underground, including benzene and arsenic, can harm human health and leach into water reservoirs.—
Camila Domonoske,
NPR,
8 July 2025
-
The tax credit was designed to support nascent technology that captures carbon emissions and stores them underground.—
Spencer Kimball,
CNBC,
3 July 2025
Adjective
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Ingredients For Sad Cake Only a few basic ingredients are needed for simple Sad Cake, including a Southerner's best kept baking secret: Bisquick Mix.—
Catherine Jessee,
Southern Living,
10 July 2025
-
The tours are accessible via phone, but each stop is kept secret throughout the journey.—
Kaela Ling,Monica Pitrelli,
CNBC,
10 July 2025
Noun
-
The North Korean cyber operatives often take on projects involving virtual currency exchanges, enabling them to more easily launder money back to the regime, undetected.—
July 8,
CBS News,
8 July 2025
-
Aside from covert operatives launching short-range drones from within Iran to strike strategic targets, Israel also relied overwhelmingly on its airpower to hit strategic and leadership targets during the campaign.—
Paul Iddon,
Forbes.com,
1 July 2025
Adjective
-
The private peninsula juts out into Flathead Lake, the largest body of fresh water west of the Mississippi River.—
Tori Latham,
Robb Report,
12 July 2025
-
But Bondi and Bongino had a contentious exchange the following day at the White House, according to a person familiar with the matter who spoke on condition of anonymity to discuss a private conversation.—
Eric Tucker,
Los Angeles Times,
12 July 2025
Noun
-
Those statements prompted the agents to acquire a warrant and arrest the couple the following day.—
Jimmy Jenkins,
AZCentral.com,
10 July 2025
-
The fish-out-of-water tale follows Mia, a young and spoiled New York heiress sent by her grandfather to Palermo, without money or luxuries, to work as a real estate agent in the family business.—
Scott Roxborough,
HollywoodReporter,
10 July 2025
Cite this Entry
“Undercover.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/undercover. Accessed 16 Jul. 2025.
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