undercover

American  

[uhn-der-kuhv-er, uhn-der-kuhv-] / ˌʌn dərˈkʌv ər, ˈʌn dərˌkʌv- /

adjective

1. working or done out of public sight; secret.

   an undercover investigation.

   Synonyms:

   hidden, clandestine, covert

2. engaged in spying or securing confidential information.

   an undercover agent.

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undercover British  

/ ˌʌndəˈkʌvə /

adjective

1. done or acting in secret

   undercover operations

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Etymology

Origin of undercover

First recorded in 1850–55; under- + cover

Explanation

Undercover means secret or disguised. A police department might send undercover officers dressed as clowns to investigate a corrupt circus. When this adjective was originally used in the mid-19th century, it meant "sheltered beneath something," but after a century or so, it was routinely used to mean "covert or clandestine." If you go undercover, you're doing some kind of secret work, usually inside an organization or group. If the other chess club members want you to be an undercover spy inside the French club, you'll have to brush up on your verb tenses.

Example Sentences

But Darth Vader’s costume, runway fashion by brands like Lanvin and Undercover, and more screens devoted to recent movies and videogames threaten to overpower the nuanced arrangements in the previous rooms.

From The Wall Street Journal • Mar. 7, 2026

The Undercover Voters are fictional profiles designed to represent a range of voters in battleground constituencies across the UK.

From BBC • Jun. 7, 2024

I tracked down some of the people behind the videos and posts shown to our Undercover Voters.

From BBC • Jun. 2, 2024

Undercover officers collected Lazarus’ DNA, and after a match was made against the bite-mark evidence, she was arrested.

From Los Angeles Times • May 21, 2024

Undercover agents rifled through Joan Fischer’s records at Brooklyn College.

From "Endgame" by Frank Brady

Related Words

• covert