Hungarian Historical Phonology bűz
bűz 'smell'
Derivative büdös
First attestation/Old Hungarian data
[coming]
Important dialectal forms
[coming]
Uralic/Pre-Hungarian reconstruction
[coming]
Cognates suggested in earlier research
None
Loan etymology
Hu bűz ← Iranian
Commentary
Due to the correspondence Hu z ~ Ir d, Iranian loan has to be early. It is unclear when the word-initial voiced stops in Hungarian emerged, and the dating of the borrowing required further research.
Conclusion
The Iranian loan etymology is convincing.
References
EWUng
Helimski 2002: Hu ← Ir
WOT