1A vessel for containing air; specifically (a) a diving bell; (b) an open-bottomed bell-shaped glass vessel used with its open end downwards to contain a gas or to protect samples; a bell jar.
2A small bubble of air; (Photography) one formed in the developer and appearing as a spot on a plate, film, or paper.
3Caving. An air-filled chamber in an otherwise water-filled cave system.
Origin
Late 18th century.
Definition of air-bell in US English:
air-bell
nounˈɛːbɛl
1A vessel for containing air; specifically (a) a diving bell; (b) an open-bottomed bell-shaped glass vessel used with its open end downwards to contain a gas or to protect samples; a bell jar.
2A small bubble of air; (Photography) one formed in the developer and appearing as a spot on a plate, film, or paper.
3Caving. An air-filled chamber in an otherwise water-filled cave system.