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

When that purchased occurred in 2010, the energy industry was focused on, among other things, discoveries of huge, cheaply accessible reservoirs of natural gas deep underground in shale formations in the U.S. and abroad. Joe Taschler, Milwaukee Journal Sentinel, "GE selling distributed power unit, which includes Waukesha site, for $3.25 billion," 25 June 2018 On March 23, 1971, the Soviet Union set off three Hiroshima-scale nuclear blasts deep underground in a remote region some 1,000 miles east of Moscow, ripping a massive crater in the earth. Sharon Weinberger, Smithsonian, "How Soviet Bomb Tests Paved the Way For U.S. Climate Science," 7 May 2018 By the 1990s, there were underground squat shops on most every street in Sofia. New York Times, "Breathing New Life Into Bulgaria’s Cold War Bunkers," 2 May 2018 Mark Henle/The Republic Almost 40 percent of Arizona’s water supply comes from an ancient source — aquifers deep underground that collected water over millions of years. Dustin Gardiner, azcentral, "Arizona aquifers are in trouble, but lawmakers want fewer rules for pumping groundwater," 4 Apr. 2018 The Original Crypts and Catacombs Tour, Dark Rome In a city as old as Rome, even layers of earth deep underground contain stories and artifacts linked to how people lived in the days of the Empire and beyond. Maresa Manara, Condé Nast Traveler, "15 Best Tours in Rome," 4 Mar. 2018 The fragment was discovered underground by crews working on the city’s utilities expansion project, The Fort Myers News-Press reported. Madeline Farber, Fox News, "Florida construction workers unearth prehistoric bone fragment, likely from mammoth," 11 Aug. 2018 Scientists have long theorized that reserves of water ice are locked underground on Mars. National Geographic, "Huge Water Reserves Found All Over Mars," 11 Jan. 2018 Avondale recently moved utility lines underground and this month started a project that will repave Dysart Road, improve landscaping and add lighting for pedestrians. Parker Leavitt, azcentral, "Readers' picks: Worst West Valley eyesores," 16 Feb. 2016

Recent Examples on the Web: Noun

There’s hardly the need when the underground of desire is a wild, open range in our pornography. David Thomson, WSJ, "Farewell My Lovely?," 14 Dec. 2018 They are entered via a series of underground poured-concrete steps, and confining even for a five-foot-tall person like me. Alexandra Lange, Curbed, "Gateway to what?," 28 June 2018 Two European firms are backing an ambitious $2.5 billion project to carry renewable electricity underground through the American heartland. Russell Gold, WSJ, "‘Extension Cord’ to Carry Green Power From Midwest to East," 10 Mar. 2019 Would the government of the U.S. leave shale oil underground? WSJ, "What Could Go Wrong With Climate Change Investing," 13 Dec. 2018 This past summer, the iconic Hotel Jerome in Aspen unveiled a conversion of the 140-year-old Aspen Times building into an events space with a sultry new underground bar, Bad Harriet, named for the hotel’s original developer. Alex Postman, Condé Nast Traveler, "If You're Skiing the Rockies This Winter, Read This First," 4 Dec. 2018 Like the kilogram standards, the Kibble balance is housed deep underground at NIST. Brian Resnick, Vox, "The world is about to redefine the kilogram," 15 Nov. 2018 The single-line, 15.5-mile heavy rail system runs above ground from Owings Mills to Mondawmin and underground between Mondawmin and Johns Hopkins Hospital. Colin Campbell, baltimoresun.com, "Transit union warned of unsafe Baltimore Metro tracks for several years," 22 June 2018 The pipeline from China to the U.S. is connected by an online marketplace that is moving commerce deeper underground on the dark web, where drug purchases can be made with anonymity. Kristina Davis, sandiegouniontribune.com, "Fentanyl has taken over America's drug market. Where is it coming from?," 17 June 2018

Recent Examples on the Web: Adjective

Manhattan houses 35,000 underground and 47,000 overhead transformers for its 10 million residents, and of those 82,000, about 35 fail every year, McGee says. Cassie Rodenberg, Popular Mechanics, "How Transformers Can Explode," 28 Dec. 2018 But many millions of Christians belong to underground or house churches that ignore government regulations. Lukas Mikelionis, Fox News, "Chinese officials burn bibles, close churches, force Christian to denounce faith amid 'escalating' crackdown," 10 Sep. 2018 The company assures that noise from the tunneling will be basically undetectable from the street, as the tunnel will be 30 feet (9.1 meters) underground and deeper in some places if the tunnel might interfere with city infrastructure. Megan Geuss, Ars Technica, "Elon Musk’s Boring Company proposes one-way, 3.6 mile tunnel to Dodger Stadium," 16 Aug. 2018 Burnet: Cool off underground and be wowed by the natural beauty of Longhorn Cavern, about 12 miles south of Burnet. San Antonio Express-News, "Your best bets for attractions all around Texas," 12 June 2018 Other studies found the dams and ponds actually helped blunt water temperature spikes, perhaps by allowing water to percolate underground and cool. Ben Goldfarb, Science | AAAS, "Beaver dams without beavers? Artificial logjams are a popular but controversial restoration tool," 7 June 2018 Since then it has been held mostly underground and out of sight. Washington Post, "Bare-knuckle boxing from a bygone era looks for a comeback," 1 June 2018 The puppy was inverted in an 8 inch pipe about 20 feet underground and crews extricated the puppy using a series of ropes. John Bacon, USA TODAY, "Must-see TV: Firefighters rescue squealing puppy from well," 17 May 2018 But by his teens, Jeter’s older cousins took him under their wing and introduced him to New Haven’s underground economy. Matthew Ormseth, courant.com, "Paroled After Two Decades In Prison, James Jeter Will Attend Trinity College This Fall," 8 July 2018

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

16 May 2019

Look-up Popularity

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

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

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

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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