Aussie crook having fed prisoner, one's stuffed (6)
I believe the answer is:
pillow
'aussie crook' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'having fed prisoner one's stuffed' is the wordplay.
'having fed' is an insertion indicator (one word is fed by another set of letters).
'prisoner' becomes 'pow' (prisoner of war).
'one's stuffed' becomes 'ill' (I am not sure about this - if you are sure you should believe this answer much more).
'pow' going around 'ill' is 'PILLOW'.
Can you help me to learn more?
(Other definitions for pillow that I've seen before include "Rest for the weary head" , "Bolster, perhaps" , "Bed cushion" , "Support for the head" , "Cushion for sleep" .)