Tunnel

Part of speech: noun, verb

Pronunciation: /ˈtʌn(ə)l/

Definitions

1. A passage or channel that runs underground or through a solid structure, or to dig such a passage through earth or rock
2. A subterranean or enclosed passage that facilitates movement or transportation, or the act of excavating such a passage through earth or rock layers
3. An underground conduit often used for transit or utilities, as well as the process of creating such a structure by removing material from the ground
4. A concealed or underground passage designed for travel or transportation, along with the process of creating such a corridor through solid material or terrain

Etymology: The word began as a barrel. In Old French, "tonel" was a small cask, a diminutive of "tone," itself a word of uncertain origin, and English borrowed the diminutive as "tonnel" in the Middle Ages, meaning a cask or barrel. The older English cousin "tunne," meaning a tun or large cask, belongs to the same family, so the word has been connected to containers from the start. The leap from barrel to underground passage came through shape. A long cylinder with an open end looks like a pipe or channel, and by the later Middle Ages the term was applied to such hollow forms in general, including passages cut through earth. The sense of a dug-out underground route is what the word has carried ever since, while its barrel meaning faded from use.

Synonyms: passage, burrow, tube, conduit, channel

Antonyms: blockage, obstruction