A paper edited before editor turned up (8)
I believe the answer is:
appeared
'turned up' is the definition.
(I've seen this before)
'a paper edited before editor' is the wordplay.
'edited' indicates anagramming the letters.
'before' says to put letters next to each other.
'editor' becomes 'ed' (abbreviation).
'paper' with letters rearranged gives 'ppear'.
'a'+'ppear'+'ed'='APPEARED'
(Other definitions for appeared that I've seen before include "Seemed - came into view" , "Turned up" , "Became visible" , "published" , "Seemed - performed - emerged" .)