The term 'CARDINAL's Topper' refers to the traditional headwear worn by cardinals in the Catholic Church. The three crossword solutions for this term are CREST (5 letters), BIRETTA (7 letters), and Redhat (6 letters). The CREST is a hat with a flat brim and a round top, often decorated with a cross or other religious symbol. The BIRETTA is a square cap with three or four ridges on the top, and is usually black or red. The redhat is a wide-brimmed hat with a tall crown, usually red in color. All of these hats are worn by cardinals as part of their official dress.