Exploit Aussies regularly (3)
I believe the answer is:
'exploit' is the definition.
(use can mean to exploit)
'aussies regularly' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'aussies' are 'USE'.
(Other definitions for use that I've seen before include "consume; exploit" , "Employ or exploit" , "Manipulate" , "Employ; consume" , "Milk" .)