Alter amendment afterward (5)
I believe the answer is:
later
'afterward' is the definition.
(I know that afterward can be written as later)
'alter amendment' is the wordplay.
'amendment' is an anagram indicator.
'alter' with letters rearranged gives 'LATER'.
(Other definitions for later that I've seen before include "After a given point in time" , "At a subsequent time" , "succeeding" , "there's more behind" , "more modern" .)