| Rating | Solver | Clue |
|---|---|---|
| VENT | Air-hole | |
| BLOWHOLE | An air hole in a casting. | |
| AIR HOLE | A hole to admit or discharge air; specifically, a spot in the ice not frozen over. | |
| AIR BLADDER | A sac or bladder full of air in an animal or plant; also an air hole in a casting. | |
| BLACK HOLE | ...of the prisoners died before morning from lack of air. ... | |