An underground or underwater passage. / A passage through or under some obstacle. / A hole in the ground made by an animal, a burrow.

(transitive) To make a tunnel through or under something; to burrow. / (intransitive) To dig a tunnel.

plural of tunnel

The act of burrowing a tunnel. / The practice of exploring tunnel. / (physics) The quantum mechanical passing of a particle through an energy barrier.

present participle of tunnel

plural of tunnelling

simple past tense and past participle of tunnel

One who makes tunnels. / A device for making tunnels.

plural of tunneler

plural of tunneller