A vent for the escape of steam or other gas.
A top-facing opening to a cavity in the ground very near an ocean's shore, leading to a marine cave from which wave water or bursts of air are expelled.
The spiracle, on the top of the head, through which cetaceans breathe.
A vertical opening in the top of a computer case that lets hot air (primarily from the CPU heat sink) escape quickly.
An unintended cavity filled with air in a casting product.
To fill or be filled with air in an unintended cavity.
a pipe, tube or canal which carries gas or liquid from one place to another
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
an enclosure or channel for electrical cable runs, telephone cables, or other conductors
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