tunnel

Definitions

• An underground or underwater passage.
• A passage through or under some obstacle.
• A hole in the ground made by an animal, a burrow.
• (computing) A wrapper for a protocol that cannot otherwise be used because it is unsupported, blocked, or insecure.
• A vessel with a broad mouth at one end, a pipe or tube at the other, for conveying liquor, fluids, etc., into casks, bottles, or other vessels; a funnel.
• The opening of a chimney for the passage of smoke; a flue.
• (mining) A level passage driven across the measures, or at right angles to veins which it is desired to reach; distinguished from the drift, or gangway, which is led along the vein when reached by the tunnel.