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
Dowding sows both leeks and celeriac under cover in module trays at the same time, around mid-March. — Sj McShane, Martha Stewart, 30 June 2026
Adjective
Throw in an undercover mission to catch a mall theft ring and Riley’s got herself a true nightmare before Christmas. — Clare Mulroy, USA Today, 26 June 2026 Whether openly or undercover, MSV doesn’t just fail shareholders. — Steve Denning, Forbes.com, 21 June 2026
Noun
Law enforcement officers working in plain clothes or undercover is nothing new. — Dana Taylor, USA Today, 22 Aug. 2025 Meanwhile, Chee goes further undercover. — Jordan Hoffman, Entertainment Weekly, 16 Mar. 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
See all Nearby Words

Cite this Entry

“Under cover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/under%20cover. Accessed 7 Jul. 2026.

Copy Citation

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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