China on replica bust (9)
I believe the answer is:
porcelain
'china' is the definition.
(thesaurus)
'on replica bust' is the wordplay.
'bust' indicates anagramming the letters.
'on'+'replica'='onreplica'
'onreplica' is an anagram of 'PORCELAIN'.
(Other definitions for porcelain that I've seen before include "Fine earthenware" , "Fine white ceramic" , "Translucent pottery" , "Fine ceramic ware" , "Jasper, perhaps" .)