underground

adverb
un·​der·​ground | \ ˌən-dər-ˈgrau̇nd How to pronounce underground (audio) \

Definition of underground

 (Entry 1 of 3)

1 : beneath the surface of the earth
2 : in or into hiding or secret operation

underground

noun
\ ˈən-dər-ˌgrau̇nd How to pronounce underground (audio) \

Definition of underground (Entry 2 of 3)

1 : a subterranean space or channel
2 : an underground city railway system
3a : a movement or group organized in strict secrecy among citizens especially in an occupied country for maintaining communications, popular solidarity, and concerted resistive action pending liberation
b : a clandestine conspiratorial organization set up for revolutionary or other disruptive purposes especially against a civil order
c : an unofficial, unsanctioned, or illegal but informal movement or group especially : a usually avant-garde group or movement that functions outside the establishment

underground

adjective
un·​der·​ground | \ ˈən-dər-ˌgrau̇nd How to pronounce underground (audio) \

Definition of underground (Entry 3 of 3)

1 : being, growing, operating, or situated below the surface of the ground
2 : conducted by secret means
3a : existing outside the establishment an underground literary reputation
b : existing outside the purview of tax collectors or statisticians the underground economy
4a : produced or published outside the establishment especially by the avant-garde underground movies underground newspapers
b : of or relating to the avant-garde underground an underground moviemaker an underground theater

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Examples of underground in a Sentence

Adverb They had been living underground as fugitives. Noun I've ridden on the New York subway, the Paris Metro, and the London Underground. joined the underground while still a teenager Adjective The drugs are supplied through an underground network. She loves the city's underground music scene.
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Recent Examples on the Web: Adverb Support pilings for the southern yellow pine boardwalk now extend 9 to 11 feet underground to the bedrock, with the new All People’s Trail now expected to last at least another 50 years. Thomas Jewell, cleveland, "All People’s Trail reopens at Shaker Lakes Nature Center after $2.5 million rebuild," 10 Nov. 2019 Stephen Byrd of Morgan Stanley, a bank, calculates that burying its transmission and distribution lines in the most vulnerable areas underground to reduce fire risk would cost $100bn. The Economist, "A three-way battle over control of PG&E," 9 Nov. 2019 The concept of a canary in a coal mine – a sensitive species that provides an alert to danger – originated with British miners, who carried actual canaries underground through the mid-1980s to detect the presence of deadly carbon monoxide gas. Stephanie Jenouvrier, The Conversation, "Emperor Penguins could march to extinction if nations fail to halt climate change," 7 Nov. 2019 Tree roots often burn underground even when the charred trees above aren’t even smoldering. Michael Cabanatuan, SFChronicle.com, "Kincade Fire is fully contained, but firefighters are sticking around," 7 Nov. 2019 Connect it to the main museum via the underground mall known as the Carrousel du Louvre, and sell a single ticket for both locations. Jason Farago, New York Times, "It’s Time to Take Down the Mona Lisa," 6 Nov. 2019 So there might be multiple ways the fungi are biding their time, the researchers say, including as fire-resistant spores underground. Jake Buehler, Science | AAAS, "‘Bodysnatching’ fungus hides inside its neighbors between blazes," 1 Nov. 2019 Located on the service level of the Capitol Visitor Center, three floors underground, the SCIF is a collection of offices and conference rooms cloaked in a double layer of metal sheathing to prevent eavesdropping. Robert P. Baird, The New Yorker, "The Circus Comes to the House Impeachment Inquiry," 29 Oct. 2019 As these habitats falter, processes hidden underground descend into chaos. Wired, "How Chaos Will Unfold if Trump Opens the Tongass to Logging," 17 Oct. 2019 Recent Examples on the Web: Noun The Great Saltworks of Salins-les-Bains, listed as a world heritage site by the United Nations’ cultural organization UNESCO, pumped naturally salted brine from deep underground to make salt. Washington Post, "Taste of the Tour: Salty riders in the town of “white gold”," 12 July 2019 Some plants have adapted to the arid climate by growing long roots that tap water from deep underground. Christina Nunez, National Geographic, "Deserts, explained," 12 June 2019 The development will include 446 parking spaces, 278 of them in garages or underground. cleveland.com, "Richmond Heights’ Belle Oaks project at mall could include another apartment building," 28 Aug. 2019 Its grass-like clumps spread by underground stems to form solid mass planting. Howard Garrett, Dallas News, "Can't grow grass in your shady yard? Try these pretty groundcovers," 23 July 2019 The data give a loose picture of what's happening both on the surface and underground. National Geographic, "Huge mystery blob found under the moon's far side," 11 June 2019 Our estimate includes also water in aquifers deep underground that the U.N.’s method does not account for. Aondover Tarhule, The Conversation, "We use satellites to measure water scarcity," 13 Aug. 2019 Drilling itself also pulls up brackish water embedded deep underground. Marissa Luck, Houston Chronicle, "Chevron Phillips, EVX Midstream partner on plastic water pipeline in Eagle Ford," 9 Aug. 2019 Descend deeper underground on rock-hewn stairs, past a life-size statue of Copernicus in the Copernicus Chamber and intricate depictions of the miners. Malavika Bhattacharya, National Geographic, "Why is everyone going to Krakow?," 23 July 2019 Recent Examples on the Web: Adjective Since Trump’s withdrawal, Tehran has begun enriching slightly above those limits, using prohibited advanced centrifuges and restarting enrichment at an underground facility. Washington Post, "Iran calls ex-FBI agent’s case a ‘missing person’ file," 11 Nov. 2019 North Korea is estimated to have between 6,000 and 8,000 underground facilities, enough to house hundreds of thousands of troops. Kyle Mizokami, Popular Mechanics, "Did U.S. Troops Have a Robot on the ISIS Raid?," 31 Oct. 2019 This underground bunker from which Churchill plotted the eventual Allied victory in Europe is a step back in time. Ben Redshaw, Cincinnati.com, "Guest Morning Line: Cincinnati Bengals fan in London offers advice for visitors," 25 Oct. 2019 The sun at 49ers’ games often drives the Levi’s suite holders into their underground tequila bunkers, giving the stands a deserted look and feel, and sound. Scott Ostler, SFChronicle.com, "Will the Warriors’ fancy Chase Center digs make them soft?," 18 Oct. 2019 The United States, with its bunker-buster bombs that could penetrate deep into underground facilities, could wait to strike. New York Times, "The Secret History of the Push to Strike Iran," 4 Sep. 2019 Over the course of 2009 and 2010, Stuxnet had destroyed more than a thousand of the six-and-a-half-foot-tall aluminum centrifuges installed in Iran’s underground nuclear enrichment facility in Natanz, throwing the facility into confusion and chaos. Andy Greenberg, WIRED, "The WIRED Guide to Cyberwar," 23 Aug. 2019 The previous administration led by John W. McCarter had taken on, for instance, $90 million in bonds, largely to build an underground facility that houses much of the museum’s world-class collection of more than 40 million biological specimens. Steve Johnson, chicagotribune.com, "Field Museum CEO Richard Lariviere will retire in 2020," 8 Aug. 2019 Because Mayor Kline is the reasons the Russians have invaded Hawkins and have started building underground facilities! Rachel Paige, refinery29.com, "Stranger Things 3," 5 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'underground.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of underground

Adverb

14th century, in the meaning defined at sense 1

Noun

1594, in the meaning defined at sense 1

Adjective

1601, in the meaning defined at sense 1

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Statistics for underground

Last Updated

14 Nov 2019

Time Traveler for underground

The first known use of underground was in the 14th century

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More Definitions for underground

underground

adverb
How to pronounce underground (audio)

English Language Learners Definition of underground

 (Entry 1 of 3)

: below the surface of the earth
: in or into a place that is hidden or secret : out of the view of the public

underground

noun
How to pronounce underground (audio)

English Language Learners Definition of underground (Entry 2 of 3)

British : a system of trains that run below the ground in a large city
: a group of people who secretly work to oppose or overthrow a government

underground

adjective
How to pronounce underground (audio)

English Language Learners Definition of underground (Entry 3 of 3)

: located or occurring below the surface of the earth
: secret and usually illegal
: of, relating to, or produced in a social and artistic world that is different and separate from the main part of society

underground

adverb
un·​der·​ground | \ ˌən-dər-ˈgrau̇nd How to pronounce underground (audio) \

Kids Definition of underground

 (Entry 1 of 3)

1 : below the surface of the earth
2 : in or into hiding or secret operation The rebels went underground.

underground

noun
un·​der·​ground | \ ˈən-dər-ˌgrau̇nd How to pronounce underground (audio) \

Kids Definition of underground (Entry 2 of 3)

1 : subway
2 : a secret political movement or group

underground

adjective
un·​der·​ground | \ ˈən-dər-ˌgrau̇nd How to pronounce underground (audio) \

Kids Definition of underground (Entry 3 of 3)

1 : located under the surface of the ground underground pipes
2 : done or happening secretly an underground revolt

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Comments on underground

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