Main Entry: ¹tun·nel

Pronunciation: \ˈtə-n^əl\

Function: noun

Etymology: Middle English tonel cask, tun, from Anglo-French, from tone tun

Date: 1508

1 : a hollow conduit or recess : tube, well
2 a : a covered passageway; specifically : a horizontal passageway through or under an obstruction b : a subterranean gallery (as in a mine) c : burrow

— tun·nel·like \-n^əl-ˌ(l)īk\ adjective