Native struck oil bargain (10)
I believe the answer is:
aboriginal
'native' is the definition.
(I know this)
'struck oil bargain' is the wordplay.
'struck' indicates an anagram (I've seen this in other clues).
'oil'+'bargain'='oilbargain'
'oilbargain' anagrammed gives 'ABORIGINAL'.
(Other definitions for aboriginal that I've seen before include "resident in Australia?" , "Autochthonous" , "Native Australian; indigenous" , "Relating to native Australians" , "First inhabitant" .)