duct

A pipe, tube or canal which carries gas or liquid from one place to another.

An enclosure or channel for electrical cable runs, telephone cables, or other conductors.

A vessel for conveying lymph or glandular secretions such as tears or bile.

A tube or elongated cavity (such as a xylem vessel) for conveying water, sap, or air.

A layer (as in the atmosphere or the ocean) which occurs under usually abnormal conditions and in which radio or sound waves are confined to a restricted path.

(no longer used) Guidance, direction.

To channel something (such as a gas) or propagate something (such as radio waves) through a duct or series of ducts.

To enclose in a duct.