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
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
Synonyms & Similar Words
Antonyms & Near Antonyms
Example Sentences
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Recent Examples of underground
Ella Gonzales, Fort Worth Star-Telegram, 4 June 2025
Archaeologists discovered the remains of thrushes in an underground waste disposal system called a cesspit connected to a taberna, or food shop, in Pollentia dating back about 2,100 years, according to a May 26 study published in the International Journal of Osteoarchaeology.
—Lauren Liebhaber, Miami Herald, 3 June 2025
Elise Cutts, Scientific American, 13 May 2025
The thriller follows a streetwise chess prodigy pulled into a brutal underground circuit where every match is a deadly gamble.
—Andreas Wiseman, Deadline, 15 May 2025
Daegan Miller
june 5, Literary Hub, 5 June 2025
The grants, largely awarded during former President Joe Biden’s final few months in the White House, were primarily for programs to capture carbon emissions and store them underground.
—Alexa St. John, Twin Cities, 30 May 2025
See All Example Sentences for underground
Adjective
How to find No Vacancy No Vacancy is a 3,800-square-foot underground space under Riot Room and Junk Punch.
—Ella Gonzales, Fort Worth Star-Telegram, 4 June 2025
Archaeologists discovered the remains of thrushes in an underground waste disposal system called a cesspit connected to a taberna, or food shop, in Pollentia dating back about 2,100 years, according to a May 26 study published in the International Journal of Osteoarchaeology.
—Lauren Liebhaber, Miami Herald, 3 June 2025
Noun
The comparisons were more than skin-deep: the researchers used gravity data to take a peek underground.
—Elise Cutts, Scientific American, 13 May 2025
The thriller follows a streetwise chess prodigy pulled into a brutal underground circuit where every match is a deadly gamble.
—Andreas Wiseman, Deadline, 15 May 2025
Adverb
Something happened to Macfarlane during all that time spent deep underground in his previous book, Underland.
—Daegan Miller
june 5, Literary Hub, 5 June 2025
The grants, largely awarded during former President Joe Biden’s final few months in the White House, were primarily for programs to capture carbon emissions and store them underground.
—Alexa St. John, Twin Cities, 30 May 2025
See All Example Sentences for underground
Recent Examples of Synonyms for underground
Adjective
-
Syria under Assad is believed to have operated an extensive clandestine nuclear program, which included an undeclared nuclear reactor built by North Korea in eastern Deir el-Zour province.—
Arkansas Online,
Arkansas Online,
5 June 2025
-
The only way to pre-empt detection by these IAEA watchdogs would be for Ukraine to withdraw from the nuclear Non-Proliferation Treaty and expel the atomic inspectors, but those moves would amount to trumpeting Kyiv’s clandestine quest to develop a nuclear warhead.—
Kevin Holden Platt,
Forbes.com,
1 June 2025
Adjective
-
It’s headquartered in the center of the city and leads its own subterranean tours.—
Ari Daniel,
Smithsonian Magazine,
15 May 2025
-
Resist imbibing the musical equivalent of slop bowls and drink from the subterranean spring.—
Kieran Press-Reynolds,
Pitchfork,
4 June 2025
Noun
-
Even now, asserting my Jewish identity feels like an act of resistance in a place where Christianity is the default assumption and performative acts of Christian prayer pervade public life and politics.—
Literary Hub,
Literary Hub,
12 June 2025
-
Is the goal to broaden appeal, reduce resistance or refocus on outcomes?—
Heather Price,
Forbes.com,
12 June 2025
Adjective
-
So is this mystery novel secretly the story of The Gilded Age and is this an undercover crossover?—
Nick Romano,
EW.com,
6 June 2025
-
The missing money controlled by Velazquez was supposed to go toward undercover narcotics operations.—
Charles Rabin,
Miami Herald,
4 June 2025
Adjective
-
Russia's latest barrages followed last weekend's covert Ukrainian operation in which agents used more than 100 drones concealed in large trucks to attack strategic bomber bases deep inside Russia.—
David Brennan,
ABC News,
8 June 2025
-
Russia’s attacks on Friday come two days after Russian President Vladimir Putin vowed to retaliate against Ukraine for its highly successful Operation Spider’s Web covert strike on Russia on June 1.—
Christopher Tremoglie,
The Washington Examiner,
6 June 2025
Adjective
-
Back in August 1993, an eight-year-old Harry, along with his older brother Prince William, then 11, enjoyed a private visit to Walt Disney World in Florida with Princess Diana.—
Madison E. Goldberg,
People.com,
7 June 2025
-
The government has no place in his private bedrooms.—
Jenna Sundel
Joshua Rhett Miller,
MSNBC Newsweek,
6 June 2025
Cite this Entry
“Underground.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/underground. Accessed 19 Jun. 2025.
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