Fruit that stays on the ground (4)

I believe the answer is:
kiwi
'fruit' is the definition.
(kiwi fruit is a kind of fruit)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for kiwi that I've seen before include "New Zealander's bird" , "Someone from New Zealand?" , "one with big bill" , "Fruit and flightless bird" , "N Zealand bird" .)
