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

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clandestine British  

/ klænˈdɛstɪn /

adjective

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

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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 )

Example Sentences

They set up clandestine camera monitoring from a public location.

From Slate • Mar. 25, 2026

Iran manages a complex, clandestine shadow-banking network globally that is facilitated by China, U.S. officials allege.

From The Wall Street Journal • Mar. 18, 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

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

But Hunt suggested they contact Bernard Barker, a Cuban American living in Miami who had done clandestine work for the CIA in the past.

From "Most Dangerous: Daniel Ellsberg and the Secret History of the Vietnam War" by Steve Sheinkin

Related Words

• covert
• fraudulent
• furtive
• hidden
• hush-hush
• illicit
• surreptitious
• underground