Hungarian Historical Phonology kés
kés 'knife; Messer'
First attestation/Old Hungarian data
[coming]
Important dialectal forms
[coming]
Uralic/Ugric/Pre-Hungarian reconstruction
(Obsolete:)
UEW: PFU *kečɜ 'knife; Messer'
Sammallahti 1988: 565: PFU *käci > PUg *käč-
Status of the Ugric etymology
Irregular
Loan etymology
None suggested
Cognates suggested in earlier research
Khanty: East (V) köčəγ, South (DN) kečə, North (O) kesi 'Messer'
Mansi: East (KU) kɑ̄si , North (So) kasaj 'Messer'
Mari: KB kəzə, U küzö 'Messer' < ? Proto-Mari *kü̆ćə (Aikio 2014: 128)
Commentary
Although the Uralic/Finno-Ugric etymology has been included in many major sources of Uralic etymology (even Sammallahti's 1988 word list), the etymology involves so much irregularity that is should be rejected. Even though the words in Hungarian, Khanty, Mansi and Mari are somehow connected, they cannot be derived from any reconstructed proto-form regularly. Hungarian shows é but Old Hungarian evidence points to an original open vowel that would fit Proto-Uralic *ä, whereas the Ob-Ugric vocalism rather points to *i. The Mari word shows irregular *ć that cannot be derived from Proto-Uralic *č (this irregularity has been noted by UEW and also by Bereczki 1988: 334, but they have still accepted the etymology). There are also irregularities in the vowel correspondences between the Mari dialects (Aikio 2014: 128). Abondolo (1996: 58) argues that based on Mari, Proto-Uralic *ü should be reconstructed, but this idea should be rejected as it would not help to solve the problems connected with the reconstruction of the alleged Proto-Uralic word.
It is possible that these words are borrowings from some unknown source ('knife' is a cultural word that gets easily borrowed). Harmatta (1997: 76) has assumed that the Uralic words are independetly borrowed from "East Iranian *keči 'knife'", a hypothetical reflex of Proto-Iranian *krti- 'knife', based on Wakhi kəz. This is a problematic explanation, as no other convnicing Iranian loans are known showing this kind of "East Iranian" development, so the etymology cannot be accepted. The Uralic words are probably loans from some unknown source.
Conclusion
No Proto-Uralic or Proto-Ugric word can be reconstructed. It is probable that the alleged cognates are independent loans from some unknown source.
References
Abondolo 1996: 58: PFU
Aikio 2014
Bereczki 1988
EWUng
Harmatta 1997
MSzFE
UEW: Proto-Finno-Ugric Uralonet