Biretta
Stiff, brimless, three- or four-sided cap worn by clergy on ceremonial occasions. It is black if worn by a priest, and purple if worn by a bishop. The biretta may be ornamented by a pompon. It is rarely used in the Episcopal Church, except in some parishes with an Anglo-catholic piety.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.