Diadem (noun)

1. A royal head ornament in the form of a band or chain worn as a symbol of sovereignty.
2. An ornamental headband worn as a symbol of authority or distinction.

Origin:

From latin diadema, from greek diadēma, from diadein to bind around, from dia- + -dein to bind.

Examples:

1. The queen wore a beautiful diadem adorned with diamonds and emeralds.
2. The king's diadem was passed down through many generations of his family.
3. The princess donned a golden diadem for her coronation ceremony.
4. The diadem was made of gold and encrusted with precious stones.
5. The diadem was a symbol of the king's authority and power.