Meaning of “duct” - Learner’s Dictionary

duct

noun [ C ] uk us /dʌkt/
BODY

a tube in the body that a liquid substance can flow through:

a tear duct
BUILDING

a tube or passage for air or wires that is part of the structure of a building:

a heating duct

(Definition of “duct” from the Cambridge Learner’s Dictionary © Cambridge University Press)