under cover
1 of 3phrase
1
: in an envelope or wrapper
2
: under concealment : in secret
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 under cover 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
CBS News, 28 Feb. 2026
As part of the preparations, two undercover SBU agents boarded a commercial vessel traveling from Constanta, Romania, past the shores of Crimea and into the port of Poti, Georgia.
—Simon Shuster, The Atlantic, 27 Feb. 2026
Rosy Cordero, Deadline, 10 Feb. 2026
Le, who was working undercover, was shot while inside his vehicle after responding to one of multiple burglaries at a cannabis business on Embarcadero near Fifth Ave.
—Carlos E. Castañeda, CBS News, 11 Dec. 2025
See All Example Sentences for under cover
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Adjective
Investigators are using tools ranging from electronic surveillance — which includes the internet — undercover operations and informants to monitor any potential threat of attack from terrorist groups Hezbollah, al Qaeda, and ISIS.
—CBS News, 28 Feb. 2026
As part of the preparations, two undercover SBU agents boarded a commercial vessel traveling from Constanta, Romania, past the shores of Crimea and into the port of Poti, Georgia.
—Simon Shuster, The Atlantic, 27 Feb. 2026
Noun
Sources close to production reveal his character is working undercover.
—Rosy Cordero, Deadline, 10 Feb. 2026
Le, who was working undercover, was shot while inside his vehicle after responding to one of multiple burglaries at a cannabis business on Embarcadero near Fifth Ave.
—Carlos E. Castañeda, CBS News, 11 Dec. 2025
See All Example Sentences for under cover
Cite this Entry
“Under cover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/under%20cover. Accessed 2 Mar. 2026.
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