tunnel

1 of 2

noun

tun·​nel ˈtə-nᵊl 

1

a

: a covered passageway

specifically : a horizontal passageway through or under an obstruction

b

: a subterranean gallery (as in a mine)

c

: burrow

2

: a hollow conduit or recess : tube, well

tunnellike

ˈtə-nᵊl-ˌ(l)īk 

adjective

tunnel

2 of 2

verb

tunneled or tunnelled; tunneling or tunnelling

ˈtən-liŋ, 

ˈtə-nᵊl-iŋ 

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

tunneler

ˈtən-lər, 

ˈtə-nᵊl-ər 

noun

Examples of tunnel in a Sentence

Noun

The train goes through a tunnel in the mountain.

The moles dug tunnels in the yard.

Verb

Workers are tunneling through the hill.

Insects had tunneled into the tree.

Recent Examples on the Web

Noun

Separation is accomplished by building elevated tracks, like Metrorail in Miami, or building tunnels or trenches to take trains below street level. —Brittany Wallman, Miami Herald, 18 Dec. 2025

A number of environmental groups and tribes have sued, challenging state permits authorizing Enbridge's plan to build a protective tunnel around the straits segment. —CBS News, 18 Dec. 2025

Verb

And Nevada Congresswoman Dina Titus sent a demand letter to Governor Lombardo, urging him to hold Elon Musk’s tunneling company accountable, make the company’s meetings with Nevada OSHA public, and answer a series of questions about how the investigation was handled. —Jessica Mathews, Fortune, 18 Dec. 2025

Recent satellite images also reveal that Iran has continued to tunnel deep under the Zagros Mountains on a different facility—called Pickaxe Mountain, or Kuh-e Kolang Gaz La, in Farsi—near Natanz. —Robin Wright, New Yorker, 12 Dec. 2025

Word History

Etymology

Noun

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

First Known Use

Noun

1508, in the meaning defined at sense 2

Verb

1795, in the meaning defined at intransitive sense 1

Phrases Containing tunnel

• a light at the end of the tunnel
• carpal tunnel syndrome
• high tunnel
• tunnel vision
• wind tunnel

Rhymes for tunnel

• bunnell
• funnel
• multifunctional

Kids Definition

tunnel

1 of 2 noun

tun·​nel ˈtən-ᵊl 

: a passage under the ground

tunnellike

-ᵊl-ˌ(l)īk 

adjective

tunnel

2 of 2 verb

tunneled or tunnelled; tunneling or tunnelling

ˈtən-liŋ, 

-ᵊl-iŋ

: to make a tunnel

Medical Definition

tunnel

noun

tun·​nel ˈtən-ᵊl 

: a bodily channel see carpal tunnel