A compound verb. With the same root cf. also k:uru -an 'to roll down', k:ur-an 'circle', (with reduplication) k:urk:ur ṭun 'to roll'. An immediate derivate from the same verb is Lak. k:uručaj (Khosr. k:urunčaj) 'round stone, roof roller'. Since PEC *ḳ in tense words > Lak. k:, it is possible, however, that this Lak. word is a result of contamination of PEC *gwērV 'round' and *mVḳ_ɨ̆rV 'roller' q.v.
Lak. k:uručaj > Arch. goroχči 'rolling stone'. Arch. goro-χ:ʷas 'to roll (intr.)', goIroI atis id. (trans.), goIroI 'ball-shaped substance' are also most probably borrowed from Lak. (sometimes with expressive pharyngealization).