Money we brought back for nut (6)
I believe the answer is:
cashew
'for nut' is the definition.
(cashew is a kind of nut)
'money we brought back' is the wordplay.
'money' becomes 'cash' (cash is a type of money).
'brought back' says the letters should be written backwards.
'we' in reverse letter order is 'ew'.
'cash'+'ew'='CASHEW'
(Other definitions for cashew that I've seen before include "nut-tree" , "Kidney-shaped nut of tropical tree" , "snack perhaps" , "Acajou" , "Common type of nut" .)