A requirement of some magazine editors (4)
I believe the answer is:
need
'a requirement' is the definition.
(I know that need is a type of requirement)
'some magazine editors' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'NEED' is hidden in the letters of 'magazine editors'.
'of' is the link.
(Other definitions for need that I've seen before include "Shortage" , "destitute state" , "''A friend in .... is a friend indeed''" , "Desideratum" , "A condition" .)