Definition from Wiktionary, the free dictionary
duct (plural ducts)
- A pipe, tube or canal which carries air or liquid from one place to another.
- heating and air-conditioning ducts
- An enclosure or channel for electrical cable runs.
- (obsolete) Guidance; direction.
- […] otherwise to express His care and love to mankind, viz., in giving and consigning to them His written word for a rule and constant director of life, not leaving them to the duct of their own inclinations. — Henry Hammond.
Derived terms 
a pipe, tube or canal which carries air or liquid from one place to another
- To channel something through a duct (or series of ducts)