Duct

Webster's Dictionary of the English Language

·noun Guidance; direction.

II. Duct ·noun Any tube or canal by which a fluid or other substance is conducted or conveyed.

III. Duct ·noun A large, elongated cell, either round or prismatic, usually found associated with woody fiber.

IV. Duct ·noun One of the vessels of an animal body by which the products of glandular secretion are conveyed to their destination.