tunnel

¹tun·nel

noun \ˈtə-n^əl\

Definition of TUNNEL

1

: a hollow conduit or recess : tube, well

2

a : a covered passageway; specifically : a horizontal passageway through or under an obstruction

b : a subterranean gallery (as in a mine)

c : burrow

— tun·nel·like \-n^əl-ˌ(l)īk\ adjective

Examples of TUNNEL

1. The train goes through a tunnel in the mountain.
2. The moles dug tunnels in the yard.

Origin of TUNNEL

Middle English tonel cask, tun, from Anglo-French, from tone tun

First Known Use: 1508

Rhymes with TUNNEL

funnel, gunnel, gunwale, runnel

²tunnel

verb

tunneled or tunnelledtunnel·ing or tunnel·ling \ˈtən-liŋ, ˈtə-n^əl-iŋ\

Definition of TUNNEL

intransitive verb

1

: to make or use a tunnel

2

physics : to pass through a potential barrier <electrons tunneling through an insulator between semiconductors>

transitive verb

: to make a tunnel or similar opening through or under; also : to make (one's way) by or as if by making a tunnel

— tun·nel·er \ˈtən-lər, ˈtə-n^əl-ər\ noun

Examples of TUNNEL

1. Workers are tunneling through the hill.
2. Insects had tunneled into the tree.

First Known Use of TUNNEL

1795

Rhymes with TUNNEL

funnel, gunnel

tun·nel

noun \ˈtən-^əl\   (Medical Dictionary)

Medical Definition of TUNNEL

: a bodily channel—see carpal tunnel

tunnel

noun    (Concise Encyclopedia)

Horizontal or nearly horizontal underground or underwater passageway. Tunnels are used for mining, as passageways for trains and motor vehicles, for diverting rivers around damsites, for housing underground installations such as power plants, and for conducting water. Ancient civilizations used tunnels to carry water for irrigation and drinking, and in the 22nd century BC the Babylonians built a tunnel for pedestrian traffic under the Euphrates River. The Romans built aqueduct tunnels through mountains by heating the rock face with fire and rapidly cooling it with water, causing the rock to crack. The introduction of gunpowder blasting in the 17th century marked a great advance in solid-rock excavation. For softer soils, excavation is accomplished using devices such as the tunneling mole, with its rotating wheel that continuously excavates material and loads it onto a conveyor belt. Railroad transportation in the 19th–20th century led to a tremendous expansion in the number and length of tunnels. Brick and stone were used for support in early tunnels, but in modern tunneling steel is generally used until a concrete lining can be installed. A common method of lining involves spraying shotcrete onto the tunnel crown immediately after excavation.