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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 …

  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 …

  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 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.

  6. tunnel noun - Definition, pictures, pronunciation and usage ...

    Definition of tunnel noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

  7. Tunnel - New World Encyclopedia

    In general, tunnels are at least twice as long as they are wide and are completely enclosed on all sides, save for the openings at each end. A tunnel may be used by pedestrians, cyclists, motor …