Jewelled headband (5)
I believe the answer is:
tiara
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">jewelled headband</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tiara that I've seen before include "Crescent-shaped headdrsss or Pope's diadem" , "Ornamental crescent-shaped headdress or Pope's diadem" , "Jewelled headwear" , "Jewelled headpiece" , "Item of jewellery" .)