1911 Encyclopædia Britannica/Patera

PATERA, the Latin name for a shallow circular vessel used for drinking or for pouring libations. The Greek name for such a vessel was φιάλη. It has no foot or stem underneath, but occasionally a boss rising in the centre inside. The term is sometimes given incorrectly in architecture to a circular disk carved with a conventional rose, which is found in many early styles, the proper term being rosette.