• A fault in a casting, produced by a bubble of air; a blowhole. • A hole to admit or discharge air; specifically, a spot in the ice not frozen over. • A local region in the atmosphere having a downward movement and offering less than normal support for the sustaining surfaces of a flying machine.
Air hole (Aëronautics) A local region in the atmosphere having a downward movement and offering less than normal support for the sustaining surfaces of a flying machine. Air' hole` (hōl`). 1. A hole to admit or discharge air; specifically, a spot in the ice not frozen over. 2. (Founding) A fault in a casting, produced by a bubble of air; a blowhole. 
[n] - a hole that allows the passage of air
noun a hole that allows the passage of air
an opening to admit or discharge air. · a natural opening in the frozen surface of a river or pond. · See