Graft, to acquire spending money (6)
I believe the answer is:
budget
'spending money' is the definition.
(I've seen this before)
'graft to acquire' is the wordplay.
'graft' becomes 'bud' (I can't justify this - if you can you should give a lot more credence to this answer).
'to acquire' becomes 'get' ('get' can be a synonym of 'acquire').
'bud'+'get'='BUDGET'
Can you help me to learn more?
(Other definitions for budget that I've seen before include "Plan of spending" , "Limit of funds" , "Cheap" , "Sum allocated for purpose" , "Chancellor's financial statement" .)