Dress has a quiet pearl ensemble (7)
I believe the answer is:
apparel
'dress' is the definition.
(I've seen this before)
'a quiet pearl ensemble' is the wordplay.
'a quiet' becomes 'ap' (I've seen this in other clues).
'ensemble' is an anagram indicator.
'pearl' anagrammed gives 'parel'.
'ap'+'parel'='APPAREL'
'has' is the link.
(Other definitions for apparel that I've seen before include "Garb, clothes" , "Fancy gear" , "formal dress?" , "Attire" , "Clothes - garments" .)