Notes: Reconstructed for the PEC level. The vowel -u- in PD may be due either to progressive labialisation or to Ablaut (*a/o). The meaning 'cream, sour cream' in Lak. and Darg. is a natural development < *'top' ("top of milk"); it may, however, also have been favoured by the influence of the verbal root *=itwVr 'to curdle' (q.v.) (cf. Lak. tata-n, PD *=ert- / *rut-). If the original meaning of the root was closer to Lezghian (i.e. "wheel set on the spindle top", whence simply "top"), it would be possible to think of an Iranian (Indo-Iranian) source like *varta- or *vr_tti- 'spinning, spinning object'.