- A round seal affixed to a papal bull.
- Medicine A large blister or vesicle.
Origin of bullaMedieval Latin, from Latin, bubble, seal.
- (medicine) A blister, vesicle, or other thin-walled cavity or lesion.
- (archaeology) A clay envelope or hollow ball, typically with seal impressions or writing on its outside indicating its contents.
- (historical) In ancient Rome, a kind of amulet or boss.
- Later, handwritten document from the papal chancellery.