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
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Recent Examples of underground
Aamir Khollam, Interesting Engineering, 31 Dec. 2025
Drug gangs, motivated by the lure of huge profits, have also developed flexible underground supply routes, which may be largely unaffected by military strikes that kill low-level gang members.
—Brian Mann, NPR, 31 Dec. 2025
Jenn Pelly, Time, 4 Dec. 2025
Its suffocating Puritanic culture is suddenly rocked by an exhilarating theater movement fostering the likes of Tamburlaine and Doctor Faustus, but also by an underground of intrigue and dissent that’s hatching schemes to blow up Parliament and extinguish royal rule.
—Peter Bart, Deadline, 4 Dec. 2025
Christopher Elliott, USA Today, 1 Jan. 2026
When millions of New Yorkers are counting down to 2026 on New Year's Eve, Mayor-elect Zohran Mamdani will be sworn in as the city's 111th mayor during a private ceremony underground.
—CBS News, 29 Dec. 2025
See All Example Sentences for underground
Adjective
The Boring Company has taken another step toward linking Las Vegas’s airport with its underground transit network.
—Aamir Khollam, Interesting Engineering, 31 Dec. 2025
Drug gangs, motivated by the lure of huge profits, have also developed flexible underground supply routes, which may be largely unaffected by military strikes that kill low-level gang members.
—Brian Mann, NPR, 31 Dec. 2025
Noun
This ambient folk album from a fixture of the UK underground uses minimalist instrumentation—little more than Roberston’s luminescent voice and brittle acoustic guitar—for maximalist feeling.
—Jenn Pelly, Time, 4 Dec. 2025
Its suffocating Puritanic culture is suddenly rocked by an exhilarating theater movement fostering the likes of Tamburlaine and Doctor Faustus, but also by an underground of intrigue and dissent that’s hatching schemes to blow up Parliament and extinguish royal rule.
—Peter Bart, Deadline, 4 Dec. 2025
Adverb
Next year, the focus is shifting underground.
—Christopher Elliott, USA Today, 1 Jan. 2026
When millions of New Yorkers are counting down to 2026 on New Year's Eve, Mayor-elect Zohran Mamdani will be sworn in as the city's 111th mayor during a private ceremony underground.
—CBS News, 29 Dec. 2025
See All Example Sentences for underground
Recent Examples of Synonyms for underground
Adjective
-
The show’s original pair of fathers, who secretly orchestrate the clandestine love affair between their children, are now mothers.—
Greg Evans,
Deadline,
7 Jan. 2026
-
Saimar Rivas, Armas’s partner and a longtime civil-rights activist, told me that he had been taken to a clandestine site run by the SEBIN, Venezuela’s intelligence agency.—
Stephania Taladrid,
New Yorker,
7 Jan. 2026
Adjective
-
The utility has a subterranean network of some 4,600 miles of pipes under the city, including significant stretches of original cast and ductile iron — some dating back to the 1800s — which pose a risk of gas leaks that could lead to an explosion.—
Robert Channick,
Chicago Tribune,
6 Jan. 2026
-
Of course, the collective memory of the city, and its residents, can take irregular, even subterranean, forms.—
Matthew Specktor,
HollywoodReporter,
5 Jan. 2026
Noun
-
Podrabinek captures the painful intersections between personal and political in a dissident’s life, and the solidarity that kept the resistance moving forward.—
Literary Hub,
Literary Hub,
10 Nov. 2025
-
Mike seems taken aback by Nina’s stony resistance.—
Noel Murray,
Vulture,
9 Nov. 2025
Adjective
-
Nine years after foiling a lucrative weapons tradeoff and delivering Roper to Syrian captors, Pine has gone undercover again, eventually reuniting with foreign investigator Angela Burr (Colman) as an MI6 operative.—
Jake Kring-Schreifels,
Time,
9 Jan. 2026
-
Can the Faithfuls work together or will the Traitors go undercover and pick off the Faithfuls one by one?—
Christopher Kuhagen,
jsonline.com,
8 Jan. 2026
Adverb
-
Some Gen Z have been desperately trying to break into the job market, sending out thousands of applications, standing on Wall Street with a sign begging for a job, and waitressing at industry conferences to stealthily hand out their resumes.—
Emma Burleigh,
Fortune,
9 Dec. 2025
-
Two minutes later, while moving through the crowd, I was stealthily pickpocketed and spent hours the next day at the police station filing a theft report.—
Lane Nieset,
Travel + Leisure,
22 Nov. 2025
Adjective
-
However, his team quickly secured their covert support in the form of money and supplies.—
Literary Hub,
Literary Hub,
7 Nov. 2025
-
Trump has authorized the Central Intelligence Agency (CIA) to carry out covert operations in the country and has left the door firmly open to unspecified land operations.—
Ellie Cook,
MSNBC Newsweek,
5 Nov. 2025
Adverb
-
Fox said the exchange between him and Wasser when he was called back to the restaurant took about 10-12 seconds, but defense attorney Karen Friedman Agnifilo suggested on Monday that the pair may have surreptitiously searched the backpack at that time and found the gun — or potentially planted it.—
Ben Brachfeld,
PEOPLE,
9 Dec. 2025
-
In a way, I am being surreptitiously employed by the owner for two minutes.—
Francesco Pacifico,
The Dial,
9 Dec. 2025
Adjective
-
Get Ready: Katy Perry Has Released a Sneak Peek of Her New Song And the internet has receipts.—
Mehera Bonner,
Marie Claire,
15 Mar. 2017
Cite this Entry
“Underground.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/underground. Accessed 11 Jan. 2026.
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