Comment: Rut. -r- in the cluster with following uvulars goes back only to PL *-l-. As for the vocalism, it can be either *u or *-e- with following labialisation (there are too few data to make the choice); external evidence seems to be in favour of the latter variant.
From some Ag. dialect the word was borrowed in Darg. Chir. ṭuIr 'shin'.