Cover victory in outstanding final part of report (5)
I believe the answer is:
duvet
'cover' is the definition.
(a duvet is a bed cover)
'victory in outstanding final part of report' is the wordplay.
'victory' becomes 'v'.
'in' is an insertion indicator.
'outstanding' becomes 'due' (an outstanding debt is due).
'final part of' indicates one should take the final letters.
The last letter of 'report' is 't'.
'v' placed within 'due' is 'duve'.
'duve'+'t'='DUVET'
(Other definitions for duvet that I've seen before include "Eiderdown" , "Bed quilt" , "Bed-cover" , "Bed cover" , "Continental quilt" .)