bulla

A blister, vesicle, or other thin-walled cavity or lesion.

A clay envelope or hollow ball, typically with seal impressions or writing on its outside indicating its contents.

In ancient Rome, a kind of amulet or boss.

Later, a handwritten document from the papal chancellery.

The tympanic part of a temporal bone (having a bubble-like appearance)

A rich Jamaican cake made with molasses and spiced with ginger and nutmeg.