Sparing in the use of resources (8)
I believe the answer is:
economic
'sparing in the use of resources' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for economic that I've seen before include "Inexpensive" , "concerned with business" , "system of money" , "Relating ot the management of wealth" , "Justified in terms of profitability" .)