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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

  • clandestinely adverb
  • clandestineness noun
  • clandestinity noun
  • unclandestinely adverb

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”; 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.

They set up clandestine camera monitoring from a public location.

From Slate • Mar. 25, 2026

Sen. Frank Church of Idaho – held extensive hearings that included eye-opening testimony about clandestine U.S. intelligence activities abroad and domestically.

From Salon • Mar. 13, 2026

In 2024, $9 billion passing through correspondent accounts maintained by U.S. banks appears to have been tied to clandestine Iranian financial activity, according to the Treasury Department.

From The Wall Street Journal • Mar. 6, 2026

Indeed, the world’s most high-stakes clandestine cat-and-mouse game is currently taking place in the race for artificial-intelligence supremacy.

From MarketWatch • Feb. 28, 2026

I spend the rest of the walk taking clandestine pranayama breaths, and soon Courtney’s opening the door of a place called the Shepherd’s House.

From "Odd One Out" by Nic Stone