Kiwi is a slur used to describe New zealanders in a derogatory way. The native bird of NZ and a popular fruit. Not necessarily a slur.
The word Kiwi is a racial slur that has been used historically to degrade and dehumanize new zealanders. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to new zealanders. If you are unsure about whether or not it is appropriate to use the word Kiwi, it is best to err on the side of caution and avoid using it in any situation.