un·der·cov·er
ˌən-dər-ˈkə-vər 
: acting or executed in secret
specifically
: employed or engaged in spying or secret investigation
an undercover agent
undercover
adverb
Examples of undercover in a Sentence
Adjective
an undercover operation to infiltrate the terrorist organization
for months she's been an undercover agent pretending to be a drug dealer
Noun
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
Recent Examples on the Web
Time, 13 Aug. 2025
Wednesday’s hearing before Magistrate Judge Shannon G. Elkins in downtown Minneapolis focused on several motions from Eichorn, including one to drop the charges and for the defense to be able to call the undercover officer who posed as a 17-year-old girl to testify.
—Mary Murphy, Twin Cities, 6 Aug. 2025
Erik Kain, Forbes.com, 1 Aug. 2025
Michael Fassbender stars as Martian, a CIA spy who’s recalled to London after years of living deep undercover in Ethiopia.
—Manuel Betancourt, Los Angeles Times, 11 June 2025
See All Example Sentences for undercover
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Adjective
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
Wednesday’s hearing before Magistrate Judge Shannon G. Elkins in downtown Minneapolis focused on several motions from Eichorn, including one to drop the charges and for the defense to be able to call the undercover officer who posed as a 17-year-old girl to testify.
—Mary Murphy, Twin Cities, 6 Aug. 2025
Noun
Meanwhile, the police send in state trooper Billy Costigan (DiCaprio) undercover to infiltrate Costello’s crime organization.
—Erik Kain, Forbes.com, 1 Aug. 2025
Michael Fassbender stars as Martian, a CIA spy who’s recalled to London after years of living deep undercover in Ethiopia.
—Manuel Betancourt, Los Angeles Times, 11 June 2025
See All Example Sentences for undercover
Cite this Entry
“Undercover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undercover. Accessed 21 Aug. 2025.
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