Elegant dress (4)
I believe the answer is:
gown
'elegant dress' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gown that I've seen before include "Garment (academic, formal, or protective)" , "A woman's long dress, or an informal dressing garment" , "Academic robe" , "Dress for formal occasions" , "Ball dress" .)