Semi-circular item of regal headwear (5)
I believe the answer is:
tiara
(Other definitions for tiara that I've seen before include "Ornamental head band" , "Decorative headband" , "Jewelled coronet" , "Small crown" , "Half-crown?" .)
I believe the answer is:
tiara
(Other definitions for tiara that I've seen before include "Ornamental head band" , "Decorative headband" , "Jewelled coronet" , "Small crown" , "Half-crown?" .)