Marketplace stocks new wool (6)
I believe the answer is:
angora
'wool' is the definition.
(thesaurus)
'marketplace stocks new' is the wordplay.
'marketplace' becomes 'agora' (agora is a kind of marketplace).
'stocks' is an insertion indicator (stocks can mean carries or contains).
'new' becomes 'n'.
'agora' enclosing 'n' is 'ANGORA'.
(Other definitions for angora that I've seen before include "Long-haired cat, goat, or rabbit" , "Breed of rabbit or cat, the former name for the Turkish capital" , "Wool from hair of goats" , "Fabric made from goat-hair from Aragon" , "Yarn made from hair of goats or rabbits" .)