Definition of: tunnel

(tun′əl) noun
1. An artificial subterranean passageway or gallery, especially one under a hill, etc., as for a railway.
2. Any similar passageway under or through something.
3. A funnel.
4. The main flue or shaft of a chimney or the like.
5. An adit or level in a mine.
—v. ·neled or ·nelled, ·nel·ing or ·nel·ling v.t.
1. To make a tunnel through.
2. To shape or make in the form of a tunnel: to tunnel a passage.
—v.i.
3. To make a tunnel. [Fusion of OF tonnelle a partridge net and tonel, dim. of tonne a cask]
—tun′nel·er or tun′nel·ler noun