Influence a paper put round fine city (6)
I believe the answer is:
affect
'influence' is the definition.
(thesaurus)
'a paper put round fine city' is the wordplay.
'paper' becomes 'ft'.
'put round' is an insertion indicator.
'fine' becomes 'f' (abbreviation).
'city' becomes 'ec' (the City of London postcode).
'f'+'ec'='fec'
'ft' going around 'fec' is 'ffect'.
'a'+'ffect'='AFFECT'
(Other definitions for affect that I've seen before include "Assume" , "Influence; make pretence of" , "impress" , "Touch (feelings); pretend (to feel)" , "Make impression on or arouse sympathy in" .)