A chapel cap is a type of headwear that is typically worn by clergymen and students. It is often referred to as a biretta or a zucchetto, which are both synonyms for chapel cap. Biretta is a traditional square-shaped hat with a flat top that is adorned with a tuft of wool or silk. Zucchetto, on the other hand, is a skullcap that is typically worn by Catholic bishops, cardinals, and the pope. Other synonyms for chapel cap include skullcap, beanie, and tam-o'-shanter. Regardless of which name is used, this type of headwear has been a symbol of religious authority and education for centuries.