tunnelling Definition

tunnel
noun

1. A constructed underground passage through or under some obstruction, eg a hill, river, road, etc, allowing access for pedestrians, vehicles, trains, etc.

Thesaurus: passage, shaft, channel, underpass.
2. An underground passage that a burrowing animal, such as a mole, digs, often one of a connected series.
3. A period of difficulty, problems, stress or exceptionally hard work.

Example: After years of poverty they could at last see the light at the end of the tunnel

verb tunnelled, tunnelling, tunneled, tunneling

intr
1. To make a tunnel through, under, etc (a hill, river, road, etc).

Form: tunnel through, under (often)
2. To make (a tunnel or passageway) through, under, etc a hill, river, road, etc.
3. To make one's way by digging a tunnel.

Form: tunnel one's way

Derivative: tunneller
noun

Derivative: tunnelling
adj, noun

Etymology: 15c: from French tonel cask.