Forward in Australian city dropping back (4)
I believe the answer is:
pert
'forward' is the definition.
(I've seen this in another clue)
'australian city dropping back' is the wordplay.
'australian city' becomes 'perth' (I've seen this in another clue).
'dropping back' means to remove the last letter.
'perth' with its final letter removed is 'PERT'.
'in' is the link.
(Other definitions for pert that I've seen before include "Saucy, lively" , "Jaunty" , "Cheeky, saucy" , "Saucy and chipper" , "Impudent, cheeky" .)