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  1. Tunnel - Wikipedia

    It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ventilation …

  2. Tunnels and underground excavations | History, Methods, Uses ...

    Dec 19, 2025 · tunnels and underground excavations, horizontal underground passageway produced by excavation or occasionally by nature’s action in dissolving a soluble rock, such as limestone. A …

  3. TUNNEL Definition & Meaning - Merriam-Webster

    The meaning of TUNNEL is a covered passageway; specifically : a horizontal passageway through or under an obstruction. How to use tunnel in a sentence.

  4. How Tunnels Work - HowStuffWorks

    Constructing a tunnel is one of the most complex challenges in the field of civil engineering. Learn about the basics behind tunnels.

  5. TUNNEL Definition & Meaning | Dictionary.com

    TUNNEL definition: an underground passage. See examples of tunnel used in a sentence.

  6. TUNNEL | definition in the Cambridge English Dictionary

    TUNNEL meaning: 1. a long passage under or through the ground, especially one made by people: 2. the long passage…. Learn more.

  7. tunnel - Wiktionary, the free dictionary

    Dec 15, 2025 · (mining) A level passage driven across the measures, or at right angles to veins which it is desired to reach; distinguished from the drift, or gangway, which is led along the vein when …