Hungarian Historical Phonology folyik
folyik 'fließen, sich ergießen, entspringen, vonstatten gehen, andauern, fortlaufen, fortdauern
First attestation/Old Hungarian data
[coming]
Important dialectal forms
[coming]
Uralic/Ugric/Pre-Hungarian reconstruction
Disputed:
UEW: PUg *pȣlɜ- 'stream bubbling; quellend fließen'
Status of the Ugric etymology
Unclear
Loan etymology
None suggested so far
Cognates suggested in earlier research
UEW:
Khanty: North (O) păli- 'hervorquellen (Wasser)', (Syn) pŏḷĭ- 'glucksen'
Mansi: South (TJ) poľćīt-, East (KU) polśīt-, West (P) poľśt- 'platschen, plätschern', North (So) polγalt-: matər polγaltawe 'etwas plätschert'
Commentary
UEW reconstructs this word as a "certain" Proto-Ugric item, but as is often the case with Proto-Ugric reconstructions, no details are given regarding the more precise quality of the vowel in the initial syllable. UEW also mentions that the word can be of onomatopoetic origin. The Khanty and Mansi words might indeed be of onomatopoetic origin, but this is less clear of Hungarian folyik.
Regarding the vocalism, the Mansi and Hungarian data could point to Proto-Ugric *u. However, the Khanty vowel (Proto-Khanty *o?) is more problematic. The vocalism of this word requires more research, but the Ugric etymology has to be considered highly uncertain.
Conclusion
The Ugric etymology remains uncertain due to phonological problems
References
UEW s.v. pȣlɜ-: Proto-Ugric Uralonet