Dictionary.com
Thesaurus.com
Synonyms

clandestine

American  
[klan-des-tin] / klænˈdɛs tɪn /

adjective

  1. characterized by, done in, or executed with secrecy or concealment, especially for purposes of subversion or deception; private or surreptitious.

    Their clandestine meetings went undiscovered for two years.

    Synonyms:
    illicit, confidential, underhand, hidden

clandestine British  
/ klænˈdɛstɪn /

adjective

  1. secret and concealed, often for illicit reasons; furtive

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Etymology

Origin of clandestine

First recorded in 1560–70; from Latin clandestīnus, from clamde, clande (unrecorded) (variant of clam “secretly” + -de, adverb particle) + -stīnus (probably after intestīnus “internal”; see intestine)

Explanation

Use the adjective clandestine to describe something that is done in secret, like your clandestine attempts to steal your brother's Halloween candy. Clandestine, an adjective imported from Latin, describes a secret, usually illegal activity. Often these things have to do with political and spy organizations. The CIA might run a clandestine operation to infiltrate terrorist organizations. Words with similar meanings include secret; covert, used especially for military matters; undercover, common in espionage; and surreptitious which emphasizes a person's efforts to keep something secret.

Keep Reading on Vocabulary.com

Vocabulary lists containing clandestine

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.

Theo joins the Royal Air Force as a pilot; Tessa is recruited for clandestine work in occupied France.

From The Wall Street Journal • Apr. 30, 2026

The first trial over his death was annulled last year following revelations that one of the judges took part in a clandestine documentary about the case.

From Barron's • Apr. 23, 2026

Others point out the long — but clandestine — history of the CIA in Mexico, dating back to the Cold War.

From Los Angeles Times • Apr. 23, 2026

They set up clandestine camera monitoring from a public location.

From Slate • Mar. 25, 2026

And his conduct in providing clandestine instructions to Adams’s cabinet undermined the constitutional authority of the executive branch in ways that would have landed him in jail in modern times.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember "clandestine" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com