A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals …

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 …

2 days ago · Explore the world’s 10 longest tunnels, record-breaking engineering marvels that push the limits of design, scale, and human ambition.

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

In this article, we'll explore what makes tunnels such an attractive solution for railways, roadways, public utilities and telecommunications. We'll look at the defining characteristics of tunnels and …

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

Define tunnel. tunnel synonyms, tunnel pronunciation, tunnel translation, English dictionary definition of tunnel. n. 1. An underground or underwater passage. 2. A passage through or …

Nov 19, 2025 · Those close to the Gateway program are tight-lipped and treading lightly to avoid more talk of terminating the rail tunnel project under the Hudson.

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 …

Tunnels are dug in types of materials varying from soft clay to hard rock.