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PlainSpell

underground

un·der·ground/ˌʌn.dəɹˈɡɹaʊnd/adjective, adverb, noun, verb

underground is spelled U-N-D-E-R-G-R-O-U-N-D: 11 letters and 3 syllables (un·der·ground). It appears 21 times per million words in written English, the 4,153rd most frequent word form (wordfreq, 2021 data). As an adjective, underground means “Below the ground; below the surface of the Earth” (English Wiktionary, September 2026).

How many letters and syllables are in underground?

Letters11: U-N-D-E-R-G-R-O-U-N-D
Syllables3: un·der·ground
In writing21 times per million words; the 4,153rd most frequent word form
Wrong spellings searchednone measured in search
Rhymes with

Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.

How common is underground?

Underground appears 21 times per million words in written English, the 4,153rd most frequent word form in the list.

Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

How do you pronounce underground?

  • UK /ˌʌn.dəˈɡɹaʊnd/
  • /ˌʊn.dɐˈɡɹʊnd/
  • US /ˌʌn.dəɹˈɡɹaʊnd/

As a noun (“The regions beneath the surface of the earth, both natural…”): /ˌʌn.dəˈɡɹaʊnd/, /ˈʌn.də.ɡɹaʊnd/, /ˌʊn.dɐˈɡɹʊnd/.

Underground has 3 syllables, split un·der·ground in writing.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-underground.wav, Wikimedia Commons (author and licence on each file's page).

Words people confuse with underground

Also written: under-ground (one word or two).

Sources: English Wiktionary (homophones, alternative spellings).

What rhymes with underground?

11 words on PlainSpell end in the same sounds as underground from its last stressed vowel (/aʊnd/):

Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).

Forms of underground

  • more underground comparative
  • most underground superlative
  • undergrounds plural, present, singular, he/she/it
  • undergrounding participle, present
  • undergrounded participle, past

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

What does underground mean?

The meanings the English Wiktionary records, quoted as written there (source below).

adjective

  1. 1

    Below the ground; below the surface of the Earth.

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

  2. 2

    Hidden, furtive, secretive.

    These criminals operate through an underground network.

  3. 3

    Of 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

adverb

  1. 1

    Below the ground.

    The tunnel goes underground at this point.

  2. 2

    Secretly.

noun

  1. 1

    The regions beneath the surface of the earth, both natural (eg. caves) and man-made (eg. mines).

  2. 2

    UKSynonym of subway: a railway that is under the ground.

    London Underground

  3. 3

    A movement or organization of people who resist political convention.

    the French underground during World War II

  4. 4

    A movement or organization of people who resist artistic convention.

verb

  1. 1

    To route electricity distribution cables underground.

  2. 2

    simple past and past participle of undergrind (a form of undergrind)

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

Underground in Spanish, French, German and Portuguese

LanguageWords
Frenchsouterrain (below the ground – see also subterranean), clandestin (hidden, furtive), underground, alternatif (outside the mainstream), sous terre, sous la terre (below the ground)
Germanunterirdisch, Untegrund- (below the ground – see also subterranean), heimlich, geheim, Untergrund- (hidden, furtive), unter der Erde (below the ground)
Portuguesesubterrâneo (below the ground – see also subterranean), clandestino, secreto (hidden, furtive), underground, alternativo (outside the mainstream), debaixo da terra (below the ground)
Spanishsubterráneo, soterraño, soterráneo (disused), soterrano (below the ground – see also subterranean), movimiento clandestino, organización clandestina (movement or organisation of people who resist…)

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.

Where does underground come from?

From Middle English undergrounde (adverb), equivalent to under + ground or under- + ground. Compare Dutch ondergrond, ondergronds, German Untergrund, Danish undergrunds.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

What to look up after underground