underground

comparative more underground · superlative most underground · alternative archaic under ground · alternative archaic under-ground

1. not comparableBelow the ground; below the surface of the Earth.

   There is an underground tunnel that takes you across the river.

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   One of the hidden glories of Victorian engineering is proper drains. Isolating a city’s effluent and shipping it away in underground sewers has probably saved more lives than any medical procedure except vaccination.

   2014 June 14, “It’s a gas”, in The Economist, volume 411, number 8891, London: The Economist Group, →ISSN, →OCLC, archived from the original on 12 Jun 2014

   Synonyms: subterranean, hypogean, belowground

2. figurativelyHidden, furtive, secretive.

   These criminals operate through an underground network.

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   At the time, South Florida had a highly active underground biker culture. Gangs including the Pagans, Outlaws and the Reapers frequently moved through the area.

   2026 July 29, Nicholas Muhoro, “Amy Billig Vanished While Hitchhiking Through Coconut Grove. Then the Calls Began”, in Skip Boring, archived from the original on 31 Jul 2026

   Synonyms: covered, concealed, dark, dern, hidden, invisible, inward, latent

3. figurativelyOf or relating to an art forms (such as music) or subculture that is outside the mainstream, especially one that is unofficial and hidden from the authorities.

   underground music

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   ‘[…]he wrote to me last week telling me about an incredible bitch of a row blazing there on account of someone having been and gone and produced an unofficial magazine called Raddled, full of obscene libellous Oz-like filth. And what I though, what Sammy and I thought, was—why not?’ ‘Why not what?’ said Tom. ‘Why not do the same thing here?’ ‘You mean an underground magazine?’ ‘Yup.’

   1991, Stephen Fry, The Liar, page 27

   "In many ways, it showed there was no longer an underground, as such. This proved that there was no longer one society with everyone agreeing how to live . . . The underground had officially come above ground, and consequently no longer existed."

   2010 March 20, James Campbell, “Barry Miles: 'I think of the 60s as a supermarket of ideas. We were looking for new ways to live'”, in The Guardian

   Synonyms: alternative, unconventional · Antonyms: mainstream

comparative more underground · superlative most underground · alternative archaic under ground · alternative archaic under-ground

1. Below the ground.

   The tunnel goes underground at this point.

   Synonyms: belowground

2. Secretly.

   Synonyms: clandestinely, in secret, on the quiet

plural undergrounds · alternative archaic under ground · alternative archaic under-ground

1. geographyThe regions beneath the surface of the earth, both natural (eg. caves) and man-made (eg. mines).
2. UKSynonym of subway: a railway that is under the ground.

   London Underground

   Synonyms: underground railway, subway

3. with definite articleA movement or organization of people who resist political convention.

   the French underground during World War II

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   Victor, please, don't go to the underground meeting tonight.

   1942, Julius J. Epstein, Philip G. Epstein, Howard Koch, Casablanca, spoken by Ilsa (Ingrid Bergman)

   Synonyms: resistance

4. with definite articleA movement or organization of people who resist artistic convention.

   Synonyms: avant-garde, counterculture

present singular third person undergrounds · participle present undergrounding · participle past undergrounded · past undergrounded · alternative archaic under ground · alternative archaic under-ground

1. To route electricity distribution cables underground.

   The utility now wants the network to be undergrounded in the urban areas, which would mean substations with 33 kV distribution swtichgear.

   2006, Janes Northcote-Green, Robert Wilson, “Design, Construction and Operation of Distribution Systems, MV Networks”, in Control and Automation of Electrical Power Distribution Systems, CRC Press, →ISBN, page 110

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   One is to underground where no other alternative will work, and this method should be used universally in urban regions as it now is in “downtown” sections.

   1962, David Pesonen, “Battles Over Energy”, in Carolyn Merchant, editor, Green Versus Gold: Sources in California's Environmental History, Island Press, published 1998, →ISBN, page 325

   Also, undergrounding may not eliminate the potential for crashes with other roadside objects, such as trees, walls, buildings, and so forth. [...] When looking at the fesibility of undergrounding utilities, the complete roadside area and nearby adjacent properties should be evaluated for potential roadside obstructions or hazards.

   2004, Don L. Ivey, C. Paul Scott, “Solutions”, in Transportation Research Board Committee on Utilities, editor, Utilities and Roadside Safety, State of the Art Report 9, Transportation Research Board, →ISBN, page 9

1. participlepastsimple past and past participle of undergrind

1. UKrail transportThe London Underground.

   Heathrow has a 28% share of passengers arriving by rail, two-thirds of whom come by the Underground.

   2019 October, John Glover, “Heathrow rail expansion”, in Modern Railways, page 71

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   Although some of the stations on ' The Branch ' have not, as yet, suffered any considerable structural alterations, all are now equipped with the familiar Underground type name boards, and as a result the imposing titles of G.N. days have been ruthlessly curtailed.

   1940 October, “Notes and News: The High Barnet Branch”, in Railway Magazine, page 569

   Synonyms: Tube