American exposed hero as addict (4)
I believe the answer is:
user
'addict' is the definition.
(thesaurus)
'american exposed hero' is the wordplay.
'american' becomes 'us'.
'exposed' indicates the central letters (outside letters removed).
The central letters of 'hero' are 'er'.
'us'+'er'='USER'
'as' is the link.
(Other definitions for user that I've seen before include "Right long-established" , "Tech support caller?" , "Utiliser" , "Drug addict (colloq.)" , "Patron" .)