Way retired copper enters in manner of vampire (7)
I believe the answer is:
dracula
'vampire' is the definition.
(I've seen this before)
'way retired copper enters in manner of' is the wordplay.
'way' becomes 'rd'.
'retired' shows that the letters should be reversed in order.
'copper' becomes 'cu' (chemical symbol).
'enters' indicates putting letters inside.
'in manner of' becomes 'ala' ('a la' means 'in the style of' in French).
'rd' reversed gives 'dr'.
'cu' inserted into 'ala' is 'acula'.
'dr'+'acula'='DRACULA'
(Other definitions for dracula that I've seen before include "Literary vampire" , "Fictional vampire" , "gothic novel" , "Stoker's Count" , "Bram Stoker novel" .)