Etymology Borrowed from Latin ductus (“leading, conducting”, noun), from dūcō (“to lead, conduct, draw”) + -tus (action noun suffix). Doublet of ductus and douit. Also via Medieval Latin ductus (“a conveyance of water; a channel”), which itself has the first mentioned etymology.
1
A pipe, tube or canal which carries gas or liquid from one place to another.
heating and air-conditioning ducts
The three motors on each bogie are force ventilated from a blower mounted in the adjacent nose-end compartment of the superstructure, the air being led by ducts and flexible bellows connections to the air inlet at the commutator end of the motor.1958 June 23, “Main-Line Diesel-Electric Locomotives for the Eastern Region”, in Railway Magazine, page 394:
2
An enclosure or channel for electrical cable runs, telephone cables, or other conductors.
3
Anatomy, Medicine, Sciences A vessel for conveying lymph or glandular secretions such as tears or bile.
4
Biology, Botany, Natural sciences A tube or elongated cavity (such as a xylem vessel) for conveying water, sap, or air.
5
Natural sciences, Physical sciences, Physics 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.
[…] 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.1650, Henry Hammond, Of the reasonableness of Christian religion:
Etymology Borrowed from Latin ductus (“leading, conducting”, noun), from dūcō (“to lead, conduct, draw”) + -tus (action noun suffix). Doublet of ductus and douit. Also via Medieval Latin ductus (“a conveyance of water; a channel”), which itself has the first mentioned etymology.
1
To enclose in a duct.
2
To channel something (such as a gas) or propagate something (such as radio waves) through a duct or series of ducts.