Some devious editor employed (4)
I believe the answer is:
used
'employed' is the definition.
('use' can be a synonym of 'employ')
'some devious editor' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'USED' can be found hidden inside 'devious editor'.
(Other definitions for used that I've seen before include "Second hand" , "Exploited - not new" , "Accustomed - exploited" , "Manipulated American editor" , "Hand-me-down" .)