tunnel >> ˈtʌn(ə)l
Definition: [noun] an artificial underground passage, especially one built through a hill or under a building, road, or river.
Example: a road tunnel through the Pyrenees
Definition: [noun] short for wind tunnel.
Definition: [noun] a long, half-cylindrical enclosure used to protect plants, made of clear plastic stretched over hoops.
Example: cover plants in rows with a cloche tunnel
Definition: [verb] dig or force a passage underground or through something.
Example: he tunnelled under the fence
Definition: [verb] (of a particle) pass through a potential barrier.