I just met the persian/hindi word "jadoo". Given its meaning and sound, I would guess that it is etymologically connected to "voodoo", possibly having a common ancestry. I would like to confirm/refute such theory. An initial quick research on it took me nowhere. I can see where each word came from to a certain extent, but I can't get any conclusive information. "voodoo" came from north africa, but I couldn't figure out for how long it has been used there. "jadoo" is a persian word, and I also can't figure out dates for usage. Since these peoples are geographically somewhat close and their cultures were in several points in history mixed/connected, the relation seem even more plausible. Does anyone know if they are connected? If nobody knows, what can I do to investigate this further, or to be certain of it?
The Farsi word "جادو" /dʒɒ:du:/ is thought to be cognate with Sanskrit "यातु" /ja:tu/, with a similar meaning. On the other hand, "voodoo" is thought to be ultimately derived from one of the Gbe languages of West Africa.
With such a large geographical distance between Indo-Arian and Gbe, no obvious possibility of contact and small phonetic similarity (/CVdu/), I'd bet my money on pure coincidence.
Voodoo or vodou in Haitian French Creole, is derived from Fon/Ewe vodun 'spirit' (pronounced [vodṹ]). As with other chance resemblances, the more you look into the etymology of both words, the less resemblance there turns out to actually be.
Another word that can mistakenly be taken to be related is juju [ǰu:ǰu:], from the Hausa word for 'fetish'. As Fon and Ewe are Niger-Congo languages, and Hausa is Afroasiatic, these words could only be related to each other by borrowing, and this seems unlikely. Juju certainly has no relationship, by borrowing or otherwise, to jadoo.
I feel pretty confident to say that jadoo/ja:tu is related to Greek ἰατρός 'physician, healer, surgeon'. The voodoo term must be a coincidence as others said.