[W/K] :: Bulla

  Bulla \Bul"la\, n.; pl. Bull[ae]. [L. bulla bubble. See Bull
     an edict.]
     1. (Med.) A bleb; a vesicle, or an elevation of the cuticle,
        containing a transparent watery fluid.
        [1913 Webster]
  
     2. (Anat.) The ovoid prominence below the opening of the ear
        in the skulls of many animals; as, the tympanic or
        auditory bulla.
        [1913 Webster]
  
     3. A leaden seal for a document; esp. the round leaden seal
        attached to the papal bulls, which has on one side a
        representation of St. Peter and St. Paul, and on the other
        the name of the pope who uses it.
        [1913 Webster]
  
     4. (Zool.) A genus of marine shells. See Bubble shell.
        [1913 Webster]

  bulla
       n 1: (pathology) an elevation of the skin filled with serous
            fluid [syn: blister, bleb]
       2: the round leaden seal affixed to a papal bull
       [also: bullae (pl)]