Go beyond available resources, because of special purpose (9)
I believe the answer is:
overspend
'go beyond available resources because of special purpose' is the definition.
I can't judge whether this defines the answer.
'because of special purpose' is the wordplay.
'because of' becomes 'over' (eg 'he's upset over it').
'special' becomes 'sp' (abbreviation).
'purpose' becomes 'end' (both can mean a goal).
'over'+'sp'+'end'='OVERSPEND'
Can you help me to learn more?
(Other definitions for overspend that I've seen before include "Consume too much" , "To run into debt" , "extravagant" , "Use too many resources" , "splurge" .)