bullae

noun

1. 1.A blister, vesicle, or other thin-walled cavity or lesion.
2. 2.A clay envelope or hollow ball, typically with seal impressions or writing on its outside indicating its contents.
3. 3.In ancient Rome, a kind of amulet or boss.
4. 4.Later, a handwritten document from the papal chancellery.
5. 5.The tympanic part of a temporal bone (having a bubble-like appearance)