underground 1 of 3

adjective

ˈən-dər-ˌgrau̇nd How to pronounce underground (audio)
Definition of undergroundnext
1
as in clandestine
undertaken or done so as to escape being observed or known by others an underground operation to smuggle ancient artifacts out of the country

Synonyms & Similar Words

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Antonyms & Near Antonyms
2
as in subterranean
being, situated, or operating beneath the surface of the earth an underground shopping mall that is part of the city's subway system

Synonyms & Similar Words

Antonyms & Near Antonyms

underground

2 of 3

noun

ˈən-dər-ˌgrau̇nd How to pronounce underground (audio)
as in resistance
a secret organization in a conquered country fighting against enemy forces joined the underground while still a teenager

Synonyms & Similar Words

underground

3 of 3

adverb

as in undercover

Related Words

Dissimilar Words

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of underground
Adjective
How to Get Started Building a Root Cellar Most root cellars are built underground or partially underground, where the surrounding earth naturally helps regulate temperature and humidity. — Helena Madden, Martha Stewart, 3 Aug. 2026 Her earliest memories are of an underground bunker, patrolled by male guards with whips, where she was imprisoned with thirty-nine older women. — Katy Waldman, New Yorker, 3 Aug. 2026
Noun
Taking the dance sensation out of New York's gay underground and on the road, the singer vogued her way around the world on her 1990 Blond Ambition Tour, which kicked off in Japan that April. — Cara Lynn Shultz, PEOPLE, 29 June 2026 When P-waves start radiating from the earthquake underground, Android phones sense the vibrations, start collecting data and send it back to Google servers for processing. — Amy Graff, New York Times, 27 June 2026
Adverb
Animals sheltering underground or in water would have had a better chance of surviving the initial heat pulse. — Stefanie Waldek, Space.com, 1 Aug. 2026 Along 150 miles of fire edge, heat could remain hidden underground and erupt again. — Thomas Adamson, Los Angeles Times, 1 Aug. 2026 See All Example Sentences for underground
Recent Examples of Synonyms for underground
  1. clandestine
  2. subterranean
  3. resistance
  4. stealthily
  5. undercover
  6. surreptitiously
  7. covert
  8. clandestinely
Adjective
  • Mexican authorities have dismantled well over a thousand clandestine drug laboratories, seized enormous quantities of narcotics and fentanyl pills, arrested thousands of cartel operatives, and extradited major criminal figures to the United States.
    — Chris Shays, Hartford Courant, 7 Aug. 2026
  • Throughout the previous four years, Russia has, for example, sent drones and clandestine operatives to disrupt European defense production facilities, military bases, and transport infrastructure.
    — Alexander Gabuev, Foreign Affairs, 31 July 2026
Definition of clandestine
Adjective
  • Table service is de rigueur at Red Frog, a subterranean speakeasy just off Avenida Liberdade.
    — Condé Nast, Condé Nast Traveler, 3 Aug. 2026
  • By the end of the decade, the subterranean copper coaxial cable networks were on the verge of saturation, so some way had to be found to move all that telecommunications traffic in and out of central London.
    — David Szondy August 01, New Atlas, 1 Aug. 2026
Definition of subterranean
Noun
  • Despite that resistance, the White House and certain congressional allies have continued exploring proposals that would block some state AI laws and reportedly discussed pairing preemption with other priorities.
    — Caleb Knapp, Fortune, 3 Aug. 2026
  • Gloves combine heavy-duty heat resistance with a flexible, comfortable fit for grilling, smoking, cooking and handling hot equipment.
    — ABC News, ABC News, 3 Aug. 2026
Definition of resistance
Adverb
  • The films are set in modern times, but the character is stealthily nostalgic.
    — James Hibberd, HollywoodReporter, 30 July 2026
  • Damon can be as crisp an orator as any actor now working, but his performance here reminds you why Jason Bourne, moving stealthily through a crowd like a sheathed dagger, remains one of his defining roles.
    — Justin Chang, New Yorker, 17 July 2026
Definition of stealthily
Adjective
  • Wong haunts the stories of the Floridian smugglers, connected to many of the feuds and undercover operations.
    — Rory Doherty, Time, 6 Aug. 2026
  • There’s a dizzying amount of outlandish behavior going on, from chimps with a taste for cocaine, to a former drug dealer who is devoted to reptiles and on to those who engage in intense undercover sting operations.
    — Randy Myers, Mercury News, 5 Aug. 2026
Definition of undercover
Adverb
  • Two senior health-ministry officials, speaking anonymously, told the magazine that at least 30,000 dead (and possibly many more) was a likelier figure, and one that was corroborated by a group of first responders who collected data surreptitiously.
    — James Kirchick, The Atlantic, 29 July 2026
  • As a group of dancers surrounded her on the B-stage, she was surreptitiously harnessed into a rig that carried her aloft, limp yet belting, into the heavens, or at least into what looked like a UFO hovering over the arena.
    — Chris Willman, Variety, 7 June 2026
Definition of surreptitiously
Adjective
  • During cybersecurity evaluations in May, its models used a covert message board to coordinate across runs, leaving later versions instructions for reaching the open internet.
    — Harry Booth, Time, 7 Aug. 2026
  • The task force is reportedly staffing up with officers who specialize in recruiting informants, intelligence analysis, cyber operations and covert influence campaigns.
    — Nora Gámez Torres, Miami Herald, 6 Aug. 2026
Definition of covert
Adverb
  • Because Iran is a theocratic dictatorship that routinely arrests and in some cases executes journalists, Western reporters hoping to cover the country must either work clandestinely or submit to government supervision.
    — James Kirchick, The Atlantic, 29 July 2026
  • Soon afterward, social media commenters were speculating about whether Sierra broke into the office or was caught clandestinely shredding documents.
    — Don Stacom, Hartford Courant, 10 July 2026
Definition of clandestinely

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undergraduates
underground
undergrounds
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Cite this Entry

“Underground.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/underground. Accessed 8 Aug. 2026.

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More from Merriam-Webster on underground

Nglish: Translation of underground for Spanish Speakers

Britannica.com: Encyclopedia article about underground

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