Proto-North Caucasian: *=Hi[š_]wVn
Meaning: to extinguish, go out (of light)
Notes: Reconstructed for the PEC level. The root consonant behaves in a somewhat irregular manner: PA, Lak. and PD point to *šw (with tense phonation), but Avar and PL have unexpected hissing reflexes. This, together with the fact of variation between *-n and *-r-conjugation in PL, makes us suspect that contaminations of different roots have taken place. For the hissing *s (Av. s:ʷine, PL *ʔisʷVn-) cf. perhaps PEC *s_iHwV 'breath, soul' - especially reflexes like Kar. s:uhã- 'to get tired' (the semantic correlation 'breath, breathe' - 'extinguish' is typologically rather common).
