under cover

1 of 3

phrase

Synonyms of under covernext
1
: in an envelope or wrapper
2
: under concealment : in secret

undercover

2 of 3

adjective

un·​der·​cov·​er ˌən-dər-ˈkə-vər How to pronounce undercover (audio)
: acting or executed in secret
specifically : employed or engaged in spying or secret investigation
an undercover agent
undercover adverb

undercover

3 of 3

noun

: a person engaged in undercover activity : spy

Synonyms of under cover

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Adjective

Noun

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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
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.
Phrase
Nolan divides the sacking of Troy into two lengthy sequences, both shot under cover of darkness but edited (by Jennifer Lame) with a magisterial clarity. — Justin Chang, New Yorker, 17 July 2026 Conversely, if only the ground robots had been employed, the defenders could have remained under cover until the robots exhausted their ammunition or blocked their advance with physical obstacles. — Vikram Mittal, Forbes.com, 17 July 2026
Adjective
The victim eventually agreed to pay the $22,450 to an unkown man posing as an undercover law enforcement officer In the parking lot of a Marathon grocery store, according to the sheriff's office. — Zachary Bynum, CBS News, 9 Aug. 2026 Barnes did not disclose the online platforms used for the operation, saying that withholding the information is necessary to protect undercover operations like Operation Cyber Shield in other jurisdictions. — Alula Alderson, Sacbee.com, 7 Aug. 2026
Noun
Goode and the Safdies began filming interviews with Tabraue and Crutchfield in 2014, with Josh sporting spy-camera glasses to try to capture Tabraue undercover, but the footage looked like crap. — Marlow Stern, Variety, 6 Aug. 2026 The result is that the majority — roughly 70% of public firms — of Self-Dealers and Value-Extractors still practicing MSV undercover are enjoying below-average as shown by the data in Figure 2 from Professor Felix Oberholzer’s book Better Simpler Strategy. — Steve Denning, Forbes.com, 21 June 2026 See All Example Sentences for under cover

Word History

First Known Use

Adjective

1920, in the meaning defined above

Noun

1962, in the meaning defined above

Time Traveler
The first known use of under cover was in 1920

Rhymes for under cover

See All Rhymes for under cover

Browse Nearby Words

undercourse
under cover
undercover
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Cite this Entry

“Under cover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/under%20cover. Accessed 16 Aug. 2026.

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Kids Definition

undercover

adjective
un·​der·​cov·​er
-ˌkəv-ər
: acting or performed in secret
an undercover scheme
especially : employed or engaged in spying or secret investigation
an undercover agent
undercover adverb
Last Updated: - Updated example sentences
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