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REFERENCE

metro

n. · adj.
US //ˈmɛˌtɹoʊ// UK //mˈɛtɹəʊ// metro
  1. 1 underground train (n.)
    A2 Elementary

    an underground train system in a large city.

    an urban rapid transit rail system, typically underground, serving a metropolitan area.

    Example

    We took the metro to the city centre because it was faster than the bus.

    Example

    The city's metro network underwent a massive expansion to accommodate the influx of commuters from the newly developed northern suburbs.

    Usage

    Often used with the definite article 'the'.

  2. 2 a large city area (n.)
    B2 Upper Intermediate Informal

    a large city and the smaller towns around it.

    a metropolitan area, including a central city and its surrounding suburbs.

    Example

    The population of the Tokyo metro is over thirty-five million people.

    Example

    Planners are struggling to manage the rapid growth of the metro, as infrastructure in the outlying districts fails to keep pace with residential development.

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  1. 3 related to a city (adj.)
    C1 Advanced Informal

    related to a large city.

    relating to or denoting a metropolis or a large urban area; a clipped form of 'metropolitan'.

    Example

    The metro police department handles security for the entire city.

    Example

    The candidate focused her campaign on metro issues, specifically targeting the concerns of young professionals living in the downtown core.

Etymology 1

From French métro, clipping of métropolitain (from Ancient Greek μήτηρ (mḗtēr, “mother”) + πόλις (pólis, “city”)), as in the Chemin de fer métropolitain, an early name for the Paris Métro. This name was a direct translation of "Metropolitan Railway", which was the original name of the earliest part of the London Underground, constructed in 1863.

Etymology 2

Clipping of metropolitan.

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