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frontier - definition and synonyms


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noun frontier pronunciation in British English /frʌnˈtɪə(r)/frontier pronunciation in British English /ˈfrʌntɪə(r)/
Word Forms
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  1. 1
    [countable] a border between two countries, especially one with official points where people or vehicles cross
    frontier between:

    the frontier between Israel and Lebanon

    frontier with:

    Italy’s frontier with Switzerland

    on/at the frontier:

    troops massing at the frontier

    1. a.
      [countable] [usually singular] the outer edge of a country or area that is the furthest point where people have started to live and build towns
    2. b.
      [singular] the western edge of the US that Europeans had reached in the 17th, 18th, and 19th centuries
    3. c.
      [only before noun] on or relating to a frontier

      frontier controls

      a frontier town

      frontier post (=official place for crossing):

      Armed police manned the frontier post.

  2. 2
    [countable] [usually plural] the most advanced or recent ideas about something
    the frontiers of knowledge/science/technology:

    Their work was on the frontiers of science.

    extend/push back the frontiers (=discover more):

    We are dedicated to experimentation, to pushing back the frontiers.



to fall over forwards so that your face hits the ground or another surface

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the activity of exploring abandoned buildings and other manmade structures

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