Hi Yahalome,
Kadi is a spelling variant of
Cadi which is a Welsh form of
Katy.
But I'm sure it can be a pet form of any name beginning with Kad-/Cad- like e.g.
Khadija, Kadena,
Cadence, Kadira etc.
If it is said to be an African name maybe it is most likely to be a pet form of
Khadija, which is an Arab name meaning "early child / born to early". (??)
Regards,
Satu