What is the meaning of 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

guidance, direction

to enclose in a duct

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

duct

Source: wiktionary.org