bulla

[boo l-uh, buhl-uh] /ˈbʊl ə, ˈbʌl ə/
noun, plural bullae
[boo l-ee, buhl-ee] /ˈbʊl i, ˈbʌl i/ (Show IPA)
1.
a seal attached to an official document, as a papal bull.
2.
an ancient Roman pendant, consisting of a rounded box containing an amulet.
3.
Pathology. a large vesicle.
4.
Zoology. a blisterlike or bubblelike prominence of a bone, as that of the tympanic bone in the skull of certain mammals.
Origin
1840-50; < Latin: bubble, also stud, boss, knob (whence Medieval Latin bulla official seal)
Examples from the web for bulla
  • Secondary spontaneous pneumothorax can be caused by lung diseases that produce the bulla, such as emphysema or asthma.
British Dictionary definitions for bulla

bulla

/ˈbʊlə; ˈbʌlə/
noun (pl) -lae (-liː)
1.
a leaden seal affixed to a papal bull, having a representation of Saints Peter and Paul on one side and the name of the reigning pope on the other
2.
an ancient Roman rounded metal or leather box containing an amulet, worn around the neck
3.
(pathol) another word for blister (sense 1)
4.
(anatomy) a rounded bony projection
Word Origin
C19: from Latin: round object, bubble
Word Origin and History for bulla
n.

1876, from Latin bulla (plural bullae), literally "bubble" (see bull (n.2)).

bulla in Medicine

bulla bul·la (bul'ə)
n. pl. bul·lae (bul'ē)

  1. A large blister or vesicle of pathological origin.

  2. A bubblelike structure.

bul'lous adj.