US /ˌʌn.dəɹˈɡɹaʊnd/ UK /ˌʌn.dəˈɡɹaʊnd/
adv noun adj Freq #3145

Meanings

  1. 1
    adj

    Below the surface of the ground.

    There is an underground tunnel that goes across the river.

  2. 2
    adv

    Below the surface of the ground.

    The pipes run underground for several miles.

  3. 3
    noun

    A city railway system that runs below the ground.

    In London the train system is called the underground.

  4. 4
    adj

    Secret or hidden, especially from the authorities.

    These criminals operate through an underground network.

Thesaurus

Synonyms
1 adj · below the surface of the... subterranean
2 adv · below the surface of the... below ground
3 noun · a city railway system that... subwaymetrotube
4 adj · secret or hidden,... clandestinecovertalternative
Word family
Forms undergrounds

Common collocations

Etymology

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

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Topics

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