Pageant crown (5)
I believe the answer is:
tiara
'pageant crown' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tiara that I've seen before include "Jewelled, ornamental headgear" , "It bejewels" , "Jewelled headwear" , "Women's head ornament" , "Decorative headgear" .)