Comment: Cf. also Tab. Düb. a=q:-, Ag. Bursh. urʕa-. Bud. and Kryz. reflect the Ablaut grade *ʔärq:e(r)- with a regular shift *ä > *a before a uvular. The adjective for 'cold' is in some languages derived from this verb, cf. Tab. Kand. ʁa-ʁu, Ag. ruʁu-f, Kryz. soʁa(j), Bud. soʁo. We should also add here (as an old participial structure, with loss of initial vowel), Kryz. q:aj 'cold' and Lezg. q:aj '(cold) wind'. A derivate from the same root is also Arch. qo-l 'ice'.