bulla

noun8

1. •
   A blister, vesicle, or other thin-walled cavity or lesion.
2. •
   (usually and especially) Such a blister that is more than 5 mm in diameter.
3. •
   Any of several hollow structures as features of bones.
4. •
   The tympanic part of a temporal bone (having a bubble-like appearance).
5. •
   A clay envelope or hollow ball, typically with seal impressions or writing on its outside indicating its contents.
6. •
   A rich Jamaican cake made with molasses and spiced with ginger and nutmeg.
7. •
   (historical) In ancient Rome, a kind of amulet or boss.
8. •
   (historical) A handwritten document from the papal chancellery.