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 relief valve set to open at a pressure below that at which a container (such as a boiler) would burst.
Any mechanism offering relief from pressure or tension, e.g. emotionally.
A United States law, codified at 18 USC §3553(f), authorizing a judge to disregard mandatory minimum sentences for some criminals with few or no prior offenses.