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
Relevance
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
as in resistance
a secret organization in a conquered country fighting against enemy forces
joined the underground while still a teenager
Synonyms & Similar Words
as in undercover
Related Words
Dissimilar Words
Example Sentences
Examples are automatically compiled from online sources to
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Recent Examples of underground
Ticked Off,
The Orlando Sentinel,
26 June 2026
Together, the pair launch an underground fight club that quickly spirals out of control.
—
Emlyn Travis,
Entertainment Weekly,
26 June 2026
Lisa Mascaro,
Los Angeles Times,
19 June 2026
Stinging insects have nested in a wall or underground.
—
Sharon Wu,
USA Today,
16 June 2026
Amy McAuliffe,
The Conversation,
26 June 2026
Spend your Friday night underground and have a great time, rain or shine.
—
Elizabeth Green,
AJC.com,
25 June 2026
See All Example Sentences for underground
Adjective
In an age of visual and underground detection, why am I delayed at a traffic signal waiting for an imaginary vehicle to enter the intersection?
—
Ticked Off,
The Orlando Sentinel,
26 June 2026
Together, the pair launch an underground fight club that quickly spirals out of control.
—
Emlyn Travis,
Entertainment Weekly,
26 June 2026
Noun
At its core, arguments are swirling over how much of the White House project is to bolster security underground, with bomb shelters and a medical facility, and how much of the costs are related to the president’s promised 999-seat ballroom on top.
—
Lisa Mascaro,
Los Angeles Times,
19 June 2026
Stinging insects have nested in a wall or underground.
—
Sharon Wu,
USA Today,
16 June 2026
Adverb
Iran was able to rebuild the capability in a matter of months, concentrating on locating future centrifuge assembly capabilities at sites buried deep underground.
—
Amy McAuliffe,
The Conversation,
26 June 2026
Spend your Friday night underground and have a great time, rain or shine.
—
Elizabeth Green,
AJC.com,
25 June 2026
See All Example Sentences for underground
Recent Examples of Synonyms for underground
Adjective
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Some may be announced publicly; others may happen in more clandestine ways.
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But clandestine flows aren’t the biggest factor behind the market calm.
Adjective
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Nearby, the subterranean Cisternerne gallery offers an eerie, atmospheric art experience in former water reservoirs.
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One type of subterranean termite worth noting is the Formosan termite (Coptotermes formosanus).
Noun
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Superconductors can carry electricity with zero resistance, but only at extremely low temperatures.
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What looked like resistance was often a different institutional instinct at work.
Adverb
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But did Spilotro go about life as an upstanding model citizen who rubbed elbows with the Vegas elite, while quietly and stealthily protecting the Mafia's financial interests in Vegas casinos?
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The six-suite Baines’ Lodge, though, has stealthily sneaked past them all as an existing camp that has received a thoughtful, artful makeover from operator Abercrombie & Kent.
Adjective
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According to his plea agreement with prosecutors, Doyle sold a Glock pistol to an undercover informant on May 20, 2025 — part of a series of transactions on Chicago’s South Side that led to his arrest on July 7, 2025, a few days after the shooting at his daughter’s party.
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Whether openly or undercover, MSV doesn’t just fail shareholders.
Adverb
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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.
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Gray-hat hackers, unlike white-hats, surreptitiously sneak into corporate systems to find security vulnerabilities.
Adjective
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After 1996, when the protease inhibitors were developed, the duty to warn continued to be an important standard when HIV status became more clinically covert.
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Authorities say the rogue drone operation led out of a former daycare in Georgia was a staging ground where multiple drones were launched on covert missions to deliver the contraband by air to 10 federal prisons at night.
Adverb
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This great disparity between reality and story, truth and history, takes on new dimensions when Robin clandestinely takes refuge at an island priory where Sister Brigid (Jodie Comer) tends to his wounds.
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Other examples of politically motivated pirate radio can be found around the world, some of them clandestinely backed by governmental intelligence agencies, but many of them existing as truly grassroots endeavors.
Cite this Entry
“Underground.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/underground. Accessed 30 Jun. 2026.
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