undercover
Americanadjective
-
working or done out of public sight; secret.
an undercover investigation.
- Synonyms:
- hidden, clandestine, covert
-
engaged in spying or securing confidential information.
an undercover agent.
adjective
Etymology
Origin of undercover
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.
Vocabulary lists containing undercover
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
“When I think of combating crime, I’m thinking … more boots on the ground, hiring more officers to tackle the crime or some type of undercover work.”
From Salon ● Sep. 6, 2026
I wish I could say that I’d arrived at the mansion on an undercover magazine assignment, but the reality was different.
From Los Angeles Times ● Sep. 5, 2026
The row centres on allegations which surfaced during undercover filming by Verbatim Investigations - founded by journalists from the Centre for Climate Reporting - and broadcast by Channel 4 News on Thursday.
From BBC ● Sep. 5, 2026
She launched herself into the mainstream in the 1960s with an expose of New York City's Playboy Club, documenting the harsh conditions she faced working undercover as a Playboy Bunny.
From BBC ● Sep. 3, 2026
“He could hear what was said over the telephone,” another detective wrote in his report, adding that the undercover “man will make good I think but will need some coaching.”
From "Killers of the Flower Moon" by David Grann
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
