air cells

Noun

air cell (plural air cells)

1. A terminal dilation of the bronchiole in lungs or similar organs where gas exchange occurs.
2. Spaces that contain air in the bones of the skull.
3. A prechamber in an indirect injection internal combustion engine.
4. An electrochemical cell that uses air as a terminal, such as the metal-air electrochemical cell.
5. Used other than figuratively or idiomatically: see air cell.
   • An air cell formed as the egg cooled and dried