Bulla

·noun A genus of marine shells. ·see Bubble shell.

II. Bulla ·noun A bleb; a vesicle, or an elevation of the cuticle, containing a transparent watery fluid.

III. Bulla ·noun The ovoid prominence below the opening of the ear in the skulls of many animals; as, the tympanic or auditory bulla.

IV. Bulla ·noun 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.