New Zealander’s answer you and I heard (4)
I believe the answer is:
kiwi
'new zealander's' is the definition.
(informal term for someone from New Zealand)
I don't understand how the remainder of the clue works.
(Other definitions for kiwi that I've seen before include "one with big bill" , "Symbol of New Zealand" , "Someone from Auckland?" , "New Zealand bird that does not fly" , "Rutherford was one" .)