Epilogue, or draft we prepared (9)
I believe the answer is:
afterword
'epilogue' is the definition.
(I've seen this in another clue)
'or draft we prepared' is the wordplay.
'prepared' indicates an anagram.
'or'+'draft'+'we'='ordraftwe'
'ordraftwe' with letters rearranged gives 'AFTERWORD'.
(Other definitions for afterword that I've seen before include "Final addition to book" , "novel conclusion, perhaps" , "I finish work" , "End matter" , "Concluding part of book" .)