Money initially earned with type of nut (6)
I believe the answer is:
cashew
'type of nut' is the definition.
(I've seen this before)
'money initially earned with' is the wordplay.
'money' becomes 'cash' (I've seen this before**).
'initially' suggests taking the first letters.
The first letters of 'earned with' is 'ew'.
'cash'+'ew'='CASHEW'
(Other definitions for cashew that I've seen before include "Kidney shaped nut" , "Kidney-shaped nut of tropical tree" , "Kind of nut" , "Edible nut" , "Common type of nut" .)