What does tunneling mean?
Tunneling has two closely related everyday meanings and one important scientific sense. In ordinary use, it means digging a passage through soil, rock, earth, or another material, usually for a road, railway, utility line, or mine. It can also mean traveling through an underground passage. A related verb use describes people or machines making their way through a difficult route, as in tunneling through snow or dense traffic. In quantum physics, tunneling names the process by which particles pass through barriers that classical physics would suggest they cannot cross. This scientific sense has become familiar through descriptions of electronic devices and nuclear reactions. The word is practical and concrete in its everyday uses, carrying the practical connotations of excavation, passage, and persistence. In physics, it is more formal and technical, describing a counterintuitive behavior of matter. The related verb “tunnel” is highly versatile, while the gerund “tunneling” is especially common in engineering reports, scientific explanations, and descriptions of movement through obstacles.
The act or process of digging or forming a passage through soil, rock, or another barrier. In physics, it is the passage of particles through a barrier that they classically lack enough energy to cross.
"The project involves tunneling through nearly two miles of granite."
The physical process is usually uncountable. The plural “tunnelings” is uncommon but can refer to separate excavation projects or distinct tunneling events.
To dig or form a passage through the ground or another material, or to move through an underground passage or difficult route.
"The miners spent years tunneling beneath the mountain."
This is the present participle of “tunnel” and can also be used before a noun, as in “tunneling equipment.”
Usually uncountable; the plural is uncommon and is used when referring to multiple distinct tunneling operations or projects.
"The engineers monitored three tunnelings beneath the ridge."
Quantum tunneling lets particles cross barriers they supposedly lack the energy to penetrate—a phenomenon that challenges everyday intuition about how matter moves.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does tunneling come from?
“Tunneling” was formed in English by adding the suffix “-ing” to “tunnel,” with the spelling reflecting British and American conventions. “Tunnel” comes through Middle English and Old French from “tonnel,” originally a small barrel or cask and then a passage or channel, ultimately related to the Latin word “tonna,” meaning “cask” or “large wine vessel.” The development from a term for a cask to one for an underground passage reflects the word’s long association with rounded, enclosed structures.
How tunneling is actually used
“Tunneling” is standard in both British and American English, with the spelling varying by one or two l’s: American usage generally has one l, while British usage traditionally has two. In physics, the term is usually uncountable and technical; in construction and civil engineering, it commonly describes excavation work. The word can also appear in computing contexts, as in “tunneling” network traffic through an intermediary connection.
Easily confused with tunneling
“Tunneling” is the usual North American spelling, while “tunnelling” is the traditional British spelling; both have the same meaning and pronunciation.