The term REGAL CROWN is used to refer to two different types of headwear: a DIADEM (6 letters) and a TIARA (5 letters). A DIADEM is a type of crown that is typically made of metal and jewels, and is worn by royalty as a symbol of power and authority. A TIARA is a more ornate type of crown, usually made of precious metals and stones, and is traditionally worn by women on special occasions. Both the DIADEM and the TIARA are considered regal crowns, and are symbols of wealth and status.