tunnel

B2 · Upper Intermediate Countable noun

n. a long hole in the ground made by an animal to live in or move through.

n. a subterranean passage or burrow excavated by an animal for habitation or transit.

“The rabbit disappeared into a small tunnel near the edge of the field.”

“The garden was riddled with complex tunnels created by moles, which had significantly damaged the root systems of the prize-winning roses.”

C1 · Advanced Countable noun Computing Technical

n. a safe way to send data over the internet by hiding it inside another type of data.

n. a communication protocol that allows for the movement of data from one network to another by encapsulating one protocol within another.

“He used a secure tunnel to access his office files from home.”

“The network administrator established an SSH tunnel to bypass the restrictive firewall and manage the remote server securely.”

B2 · Upper Intermediate

v. to dig a long hole under or through something.

v. to excavate a tunnel through or under a physical barrier. Often used with 'through' or 'under'.

“The prisoners tried to tunnel under the wall to escape.”

“The construction crew had to tunnel through solid granite to complete the new highway extension before the winter deadline.”

C2 · Proficiency Science Technical

v. when a tiny particle passes through a barrier that it normally should not be able to cross.

v. to undergo the quantum-mechanical phenomenon where a particle penetrates a potential energy barrier that it classically lacks the energy to surmount.

“In quantum physics, particles can sometimes tunnel through barriers.”

“Quantum tunneling is a fundamental process in nuclear fusion, allowing protons to overcome their mutual electrostatic repulsion despite having insufficient kinetic energy.”