Account concerning fortified wine (6)
I believe the answer is:
report
'account' is the definition.
(I know that account can be written as report)
'concerning fortified wine' is the wordplay.
'concerning' becomes 're' (both can mean on a particular topic).
'fortified wine' becomes 'port' (port is a type of fortified wine).
're'+'port'='REPORT'
(Other definitions for report that I've seen before include "Relate; gun noise" , "A crack" , "Account; loud noise" , "Pupil's assessment" , "Formal document" .)