Upset about antipodean (3)
I believe the answer is:
tip
'upset' is the definition.
(I've seen this in another clue)
'about antipodean' is the wordplay.
'about' indicates the answer is hidden within the clue.
'TIP' is hidden in the letters of 'antipodean'.
(Other definitions for tip that I've seen before include "Pointed extremity" , "End - pourboire" , "single piece of asparagus, perhaps" , "List, gratuity" , "Helpful information; end" .)