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

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.
Adjective
According to his plea agreement with prosecutors, Doyle sold a Glock pistol to an undercover informant on May 20, 2025 — part of a series of transactions on Chicago’s South Side that led to his arrest on July 7, 2025, a few days after the shooting at his daughter’s party. Sam Charles, Chicago Tribune, 22 June 2026 Whether openly or undercover, MSV doesn’t just fail shareholders. Steve Denning, Forbes.com, 21 June 2026
Noun
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 First, in February 2008, a Dutch TV station aired a confession allegedly made by van der Sloot and captured on a hidden camera by Patrick van der Eem, a businessman working undercover for a Dutch journalist. Lynsey Eidell, PEOPLE, 30 May 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

Browse Nearby Words

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Cite this Entry

“Under cover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/under%20cover. Accessed 25 Jun. 2026.

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
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