The inverted bell is a metaphorical name for geometric shape that resembles a bell upside down.
In architecture, the term is applied, e.g., to describe the shape of the capitals of Corinthian columns.
The inverted bell is used in shape classification in pottery, often featured in archaeology as well as in modern times.
The inverted bell curve is sometimes called well curve.
Bell-mouth spillway at Llyn Celyn
Inverted-bell beakers from the Beaker culture