• synonyms


[adverb, uhn-der-ground; adjective, noun, verb uhn-der-ground]
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  1. beneath the surface of the ground: traveling underground by subway.
  2. in concealment or secrecy; not openly: subversion carried on underground.
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  1. existing, situated, operating, or taking place beneath the surface of the ground.
  2. used, or for use, underground.
  3. hidden or secret; not open: underground political activities.
  4. published or produced by political or social radicals or nonconformists: an underground newspaper.
  5. avant-garde; experimental: an underground movie.
  6. critical of or attacking the established society or system: underground opinion.
  7. of or for nonconformists; unusual: an underground vegetarian restaurant.
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  1. the place or region beneath the surface of the ground.
  2. an underground space or passage.
  3. a secret organization fighting the established government or occupation forces: He fought in the French underground during the Nazi occupation of France.
  4. (often initial capital letter) a movement or group existing outside the establishment and usually reflecting unorthodox, avant-garde, or radical views.
  5. Chiefly British. a subway system.
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verb (used with object)
  1. to place beneath the surface of the ground: to underground utility lines.
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Origin of underground

First recorded in 1565–75; under- + ground1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for underground

subterranean, buried, clandestine, hidden, experimental, private, revolutionary, covert, alternative, avant-garde, radical, sunken, underfoot, subterrestrial, concealed, hush-hush, resistant, surreptitious, unbowed, unconventional

Examples from the Web for underground

Contemporary Examples of underground

Historical Examples of underground

  • A rude ladder was the usual mode of entrance into these underground dwellings.

    English Villages

    P. H. Ditchfield

  • The five lowest levels were underground and all were labelled "Mineral Industries."

  • There, in his underground realm, she reigns all the cold winter months.

    Classic Myths

    Mary Catherine Judd

  • Life, life, everywhere, and seemingly this underground world was endless.

    Two Thousand Miles Below

    Charles Willard Diffin

  • The lanes of this underground village were still fast asleep.

British Dictionary definitions for underground


adjective (ˈʌndəˌɡraʊnd)
  1. occurring, situated, or used below ground levelan underground tunnel; an underground explosion
  2. secret; hiddenunderground activities
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adverb (ˌʌndəˈɡraʊnd)
  1. going below ground levelthe tunnel led underground
  2. into hiding or secrecythe group was driven underground
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noun (ˈʌndəˌɡraʊnd)
  1. a space or region below ground level
    1. a movement dedicated to overthrowing a government or occupation forces, as in the European countries occupied by the German army in World War II
    2. (as modifier)an underground group
  2. the underground an electric passenger railway operated in underground tunnelsUS and Canadian equivalent: subway
  3. (usually preceded by the)
    1. any avant-garde, experimental, or subversive movement in popular art, films, music, etc
    2. (as modifier)the underground press; underground music
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for underground


1570s, "below the surface," from under + ground (n.). As an adjective, attested from c.1600; figurative sense of "hidden, secret" is attested from 1630s; adjectival meaning "subculture" is from 1953, from World War II application to resistance movements against German occupation, on analogy of the dominant culture and Nazis. Noun sense of "underground railway" is from 1887 (shortened from phrase underground railway, itself attested from 1834).

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Online Etymology Dictionary, © 2010 Douglas Harper