Annulet
AN'NULET, noun [Latin annulus, a ring.]
In architecture, a small square member in the Doric capital, under the quarter round; also a narrow flat molding, which is common to many places, as in the bases or capitals; called also a fillet, or listil, or cincture, or a list, timea, eye brow or square rabbit.
In heraldry, a little circle, borne as a charge is coats of arms; formerly reputed a mark of nobility and jurisdiction; it being the custom of prelates to receive their investiture per baculum et annulum, by staff and ring. It denotes also strength and eternity, by its circular form. Among the Romans, it represented liberty and distinction of rank. It denotes also difference, or mark of distinction, which the fifth brother of a family ought to bear on his coat of arms.