Alternative name in Australia sometimes (5)
I believe the answer is:
alias
'alternative name' is the definition.
(I've seen this before)
'in australia sometimes' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ALIAS' is hidden within 'australia sometimes'.
(Other definitions for alias that I've seen before include "False or assumed name" , "stage name, perhaps" , "Cabbage salad" , "it may be assumed" , "one's assumed" .)