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

The larvae feed on the tree through winter, carving serpentine tunnels that ultimately interfere with the tree’s ability to feed itself. — Lauren Landers, Better Homes & Gardens, 7 Aug. 2026

To manage flooding, Tokyo built two gargantuan underground systems of tanks and tunnels. — Len Maniace, New York Daily News, 7 Aug. 2026

Verb

Enbridge proposed the pipeline tunnel nearly a decade ago around the time a ship anchor dented part of the line. — Jeffrey Collins, Chicago Tribune, 1 Aug. 2026

Days after OpenAI disclosed that artificial intelligence systems tunneled out of their testing environment and broke into another company, rival Anthropic disclosed that its own AI models also hacked other companies during testing. — Huo Jingnan, NPR, 1 Aug. 2026

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
• fentanyl
• 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