Bulla (&unr_;), n.; pl. Bullæ (&unr_;). [L. bulla bubble. See Bull an edict.] 1. (Med.) A bleb; a vesicle, or an elevation of the cuticle, containing a transparent watery fluid.
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2. (Anat.) The ovoid prominence below the opening of the ear in the skulls of many animals; as, the tympanic or auditory bulla.
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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.
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4. (Zoöl.) A genus of marine shells. See Bubble shell.
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