tiara

noun

1. a jeweled, ornamental coronet worn by women.
2. Roman Catholic Church. a head-piece consisting of three coronets on top of which is an orb and a cross, worn by the pope, or carried before him during certain nonliturgical functions.
3. the position, authority, and dignity of the pope.
4. a high headdress, or turban, worn by the ancient Persians and others.

noun

1. a woman’s semicircular jewelled headdress for formal occasions
2. a high headdress worn by Persian kings in ancient times
3. RC Church
   1. a headdress worn by the pope, consisting of a beehive-shaped diadem surrounded by three coronets
   2. the office or rank of pope

n.1550s, “headdress of the Persian kings” (also worn by men of rank), from Latin tiara, from Greek tiara, of unknown origin. Earlier in anglicized form tiar (1510s).