Air" hole` (hOl`).
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.
© Webster 1913
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.
© Webster 1913