undercover

1 of 2

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

2 of 2

noun

: a person engaged in undercover activity : spy

Examples of undercover 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
Based on an incident that had happened 10 years earlier, the book chronicles the harrowing story of two undercover LAPD patrol officers who are kidnapped during a routine traffic stop that goes horribly wrong. Chris Koseluk, The Hollywood Reporter, 28 Feb. 2025 Russo turned stool pigeon within a month of his November 2017 arrest for selling a kilo of cocaine to an undercover agent. John Annese, New York Daily News, 26 Feb. 2025
Noun
Want to see what else is up for grabs during Wayfair’s undercover Kelly Clarkson Home sale? Shea Simmons, People.com, 6 Feb. 2025 The Confidential Rental and Leasing Office, created under former Commissioner Ray Kelly, has an important core purpose: to give investigators, including undercovers, a way to procure and use a range of vehicles that don’t automatically give them away, which standard unmarked cop cars tend to do. New York Daily News Editorial Board, New York Daily News, 16 Jan. 2025 See All Example Sentences for undercover

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 undercover was in 1920

Browse Nearby Words

Cite this Entry

“Undercover.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undercover. Accessed 11 Mar. 2025.

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

More from Merriam-Webster on undercover

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!