Porter prepared an account (6)
I believe the answer is:
report
'an account' is the definition.
('report' can be a synonym of 'account')
'porter prepared' is the wordplay.
'prepared' is an anagram indicator.
'porter' is an anagram of 'REPORT'.
(Other definitions for report that I've seen before include "Describe with a bang" , "Sudden noise; account of progress" , "A crack" , "Pupil's assessment" , "Written account" .)