- Air aperture
- Air hole
- Air outlet
- Air-hole
- Aperture
- Opening
- Outlet
- A cavern in a cliff, at the water level, opening to the
air at its farther extremity, so that the waters rush in with each
surge and rise in a lofty jet from the extremity.
- A nostril or spiracle in the top of the head of a whale
or other cetacean.
- A hole in the ice to which whales, seals, etc., come to
breathe.
- An air hole in a casting.
- A hole to admit or discharge air; specifically, a spot in
the ice not frozen over.
- A fault in a casting, produced by a bubble of air; a
blowhole.
- An air sac, sometimes double or variously lobed, in the
visceral cavity of many fishes. It originates in the same way as the
lungs of air-breathing vertebrates, and in the adult may retain a
tubular connection with the pharynx or esophagus.
- A sac or bladder full of air in an animal or plant; also
an air hole in a casting.
- A dungeon or dark cell in a prison; a military lock-up or
guardroom; -- now commonly with allusion to the cell (the Black Hole)
in a fort at Calcutta, into which 146 English prisoners were thrust by
the nabob Suraja Dowla on the night of June 20, 17656, and in which 123
of the prisoners died before morning from lack of air.