European shopping centre first to get proficient with plastic (9)
I believe the answer is:
malleable
'plastic' is the definition.
(thesaurus)
'european shopping centre first to get proficient' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'shopping centre' becomes 'mall' (a mall is a large shopping complex).
'first' means one lot of letters go next to another.
'to get' means one lot of letters go next to another.
'proficient' becomes 'able' (able can mean capable or proficient).
'e' put after 'mall' is 'malle'.
'malle'+'able'='MALLEABLE'
'with' is the link.
(Other definitions for malleable that I've seen before include "Soft" , "Tractable" , "Able to be shaped" , "Being adaptable" , "Able to be hammered" .)