6 letters · 10 points in Scrabble
noun an ornamental jeweled headdress signifying sovereignty
originFrom Middle English diademe, dyademe, from Old French diademe, from Latin diadēma, from Ancient Greek διάδημα (diádēma, “band, especially worn around a tiara”), from διαδέω (diadéō, “bind around”).
Etymology from Wiktionary, CC BY-SA 3.0