Khanty (Ostyak):čim- (Trj.) 'gären, aufsteigen (der Teig)', sim- (O) 'infolge von Feuchtigkeit mürbe werden, verderben; gärend aufsteigen (der Teig)'
K. Reshetnikov's notes:It is, indeed, quite difficult to explain the correspondence Perm. š ~ Khanty č. Should we treat Khanty *čim- as an old (Proto-Khanty or even Proto-Ob-Ugric) loan from Permic (Proto-Komi?) - with the substitution *š > *č for lack of *š in Proto-Khanty (as well as in Proto-(Ob)-Ugric)? Note that Permic loanwords in Khanty having š in the place of Permic š don't contradict this interpretation: they either were borrowed (chiefly from Komi) into some separate Khanty dialects, where š is present (being a result of a secondary development of *č-) or regularly arose in the same dialects as reflexes of Proto-Khanty words with *č- borrowed from Permic. For the vowel substitution (Permic *ȯ > Khanty *i) cf. ИВПЯ 152.