Hungarian Historical Phonology süly
süly 'Skorbut, Scharbock, Feigwarze, Geschwür'
First attestation/Old Hungarian data
? 1109 Sild (see EWUng 1372, s.v. süly)
Important dialectal forms
[coming]
Uralic/Ugric/Pre-Hungarian reconstruction
Disputed: UEW: *ćiklä (ćüklä), ćikĺä (ćükĺä) 'wart; Warz'
Status of the Ugric etymology
[coming]
Loan etymology
Hu ← Turkic *šiγül
Cognates suggested in earlier research
See YSuS süklä
Commentary
It has been assumed that Hungarian süly reflects Proto-Uralic *ćüklä, but this eetymology shows irregular developments, notably the irregular reflex s of Proto-Uralic *ć. Aikio (UED draft, 152) rejects the Uralic background of the Hungarian word because of these irregularities. A more probable explanation for the Hungarian word is that it is borrowed from West Old Turkic *šiγül (~ East Old Turkic sigil, sögöl 'wart'; WOT 747-749). Many parallels can be found for Hungarian s corresponding to the reconstructed West Old Turkic *š and the attested East Old Turkic s, such as Hu sima 'smooth' ~ West Old Turkic *šïma id. (WOT 726-728) and Hu sör 'beer' ~ West Old Turkic *šire id. (WOT 738-740). It is also notable that the meanings found among the Turkic languages are more diverse, cf. East Old Turkic sögnägü ‘a pustule that appears between the nail and the skin’, Chagatay siwel ‘a hard lump which emerges on a hand or a limb’, whereas almost all of the Uralic cognates denote 'wart'.
WOT assumes that also the alleged Mordvin and Mari cognates are loans from the same Turkic word (see the discussion). Bereczki (2013: 228) supports the Uralic etymology of these words.
Conclusion
The Turkic loan etymology is more convincing.
References
Aikio UED draft: Hu not < PU
Bereczki 2013: 228: PU
EWUng 1372, s.v. süly: PU
MSzFE: 556-557, s.v. süly
UEW: PU Uralonet