Jewelled headdress: it elevated a painter (5)
I believe the answer is:
tiara
'jewelled headdress' is the definition.
(tiara is a kind of jewelled headdress)
'it elevated a painter' is the wordplay.
'elevated' says the letters should be written backwards.
'painter' becomes 'ra'.
'it' backwards is 'ti'.
'ti'+'a'+'ra'='TIARA'
(Other definitions for tiara that I've seen before include "Great delight" , "Item of jewellery" , "Ornamental head band" , "Jewelled coronet" , "Decorative headband" .)