Some magazine editor's requirement (4)
I believe the answer is:
need
'requirement' is the definition.
(synonyms)
'some magazine editor's' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'NEED' can be found hidden inside 'magazine editors'.
(Other definitions for need that I've seen before include "Require; want" , "Necessitate" , "Distressful situation" , "Desideratum" , "'miss'" .)