Copied a page written by editor (4)
I believe the answer is:
aped
'copied' is the definition.
('ape' can be a synonym of 'copy')
'a page written by editor' is the wordplay.
'page' becomes 'p'.
'written by' is a charade indicator (letters next to each other).
'editor' becomes 'ed'.
'a'+'p'+'ed'='APED'
(Other definitions for aped that I've seen before include "Followed" , "Caricatured" , "Imitated like primate" , "took off" , "Imitated in every aspect" .)