Changed novel later with editor (7)
I believe the answer is:
altered
'changed' is the definition.
('alter' can be a synonym of 'change')
'novel later with editor' is the wordplay.
'novel' is an anagram indicator (letters in a new or novel order).
'with' is a charade indicator (letters next to each other).
'editor' becomes 'ed' (abbreviation).
'later' is an anagram of 'alter'.
'alter'+'ed'='ALTERED'
(Other definitions for altered that I've seen before include "Metamorphosed" , "Reformed" , "Treadle (anag)" , "Change" , "Changed, adapted" .)