A second amount of money editor accepted (7)
I believe the answer is:
assumed
'accepted' is the definition.
('assume' can be a synonym of 'accept')
'a second amount of money editor' is the wordplay.
'second' becomes 's' (common abbreviation).
'amount of money' becomes 'sum' (synonyms).
'editor' becomes 'ed' (abbreviation).
'a'+'s'+'sum'+'ed'='ASSUMED'
(Other definitions for assumed that I've seen before include "Took for granted" , "Took to be the case" , "Fancied" , "Took (control)" , "Accepted as true without actual proof" .)