under cover

1 of 3

phrase

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
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Adjective
Comeaux also said undercover officers would focus on drug enforcement. Matthew Ablon, CBS News, 1 June 2026 The Washington Nationals are in full damage control after an undercover journalist with the O’Keefe Media Group caught now former Director of Community Relations Sean Hudson claiming to be religiously discriminating against Catholic starting pitcher Trevor Williams. Jon Root Outkick, FOXNews.com, 30 May 2026
Noun
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 The Agency‘s second season will continue following Martian, a CIA agent living undercover in his own life. Rosy Cordero, Deadline, 19 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

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Cite this Entry

“Under cover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/under%20cover. Accessed 2 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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