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.
Steve Coogan is terrific in a rare dramatic role, as is Tom Burke as cop teetering on the edge as he falls dangerously deep into his undercover persona.
From MarketWatch • May 31, 2026
The BBC's Yogita Limaye was the first foreign journalist to enter Myanmar - undercover with colleagues - after the 7.7 magnitude tremor, which reached as far as Thailand, China and India, struck.
From BBC • May 28, 2026
When Conradt didn’t show at the undercover house, NBC and police went to his home in an attempt to serve a search warrant.
From Los Angeles Times • May 27, 2026
On the other hand, these aggregators are bringing news stories to audiences who might not be getting them elsewhere – some of the undercover voters wouldn't otherwise be seeing much about politics.
From BBC • May 16, 2026
No undercover wizard would have chosen to pose as a Magizoologist at that period.
From "Fantastic Beasts and Where to Find Them" by J.K. Rowling
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.
