Malevolent woman, mean having severed head, eats Australian native (9,4)
I believe the answer is:
witchetty grub
'australian native' is the definition.
(australian term for white moth larvae)
'malevolent woman mean having severed head eats' is the wordplay.
'malevolent woman' becomes 'witch'.
'mean' becomes 'petty'.
'having severed head' means to remove the first letter.
'eats' becomes 'grub' (synonyms).
'petty' with its initial letter taken away is 'etty'.
'witch'+'etty'+'grub'='WITCHETTY GRUB'
(Other definitions for witchetty grub that I've seen before include "Example of Oz cuisine" , "fare to Australia" , "Australians eat it" , "bush tucker" .)