Notes: The PN root has (as far as we know) no parallels in Dagestan languages, but has good correspondences in Hurro-Urartian: PHU *χas- (Hurr. χaž-, Ur. χaš-) "hear". See Diakonoff-Starostin 1986, 46.
Notes: A Tsez.-Lezgh. isogloss; within Tsezian attested only in one language, thus not very reliable. Problematic also is the retention of -r- in Bezht. (normally all resonants in clusters are dropped in PTs); this could suggest an old structure like *χwĕćVrV with later reduction.
Notes: An And-Lezg. isogloss. A rather uncertain case, because of some unclear features of the stem structure in PL. Still, it seems hard to separate forms like Tab. χirχil 'straw' and Tind. χʷaχʷar id.
Notes: A Nakh-Avar isogloss. Cf. perhaps Osset. xɨl / xilä 'quarrel' (Abayev 1989, 258: the Iranian etymology does not look convincing, and a Caucasian source is probable).
Notes: An Av.-Lezg. isogloss. Probable, but represented only in three languages, and thus not very reliable (note also phonetic problems: if we reconstruct medial *-r-, as suggested by the Av. form, we would rather expect *χʷ, not *χ:ʷ in PL).
Notes: An Aand-Lezg. isogloss. Except for metathesis (rather a frequent feature), all correspondences are regular.
An interesting form is Arch. duχ:ur 'farmstead': this is probably an old loanword from Av.-And. with a later Arch. change r- > d- (duχ:ur < *riχ:ʷV-r), thus constituting an etymological doublet with Arch. χIor 'village'.
Notes: Reconstructed for the PEC level. Labialisation in Andian is irregular (one would rather expect a form like *χilV). There are two possible explanations: either we should rather reconstruct PEC *χ_ǟwɫV with a cluster (yielding labialisation in And. and simplified in PN and PL), or we should assume that And. χʷolo (isolated among Andian languages) is a loanword from Nakh (with labialisation rendering the Nakh narrow -ō- = /-wō-/).
We can also pay attention to Lak. χ:ala- in χ:ala-baḳu 'haystack' which can also correspond to the PN and PL forms - although synchronically Lak. χ:ala- is the oblique base of χ:ulū 'hay', which has a different EC origin (see *χǖɫV). Both roots must have merged in Lak. for phonetic reasons.
Notes: An Av.-And.-Tsez. isogloss. The PTs form contains a rare phoneme *ʁ- which in this case must be just a variant of PTs *χ (*ʁ- is reconstructed on basis of PTsKh *-ʁu present only in the compound *biƛ̣-ʁu; we may think of a secondary voicing in this position). There exists a chance of finding a Lezghian cognate: PL *χIap:, obl. *χIop:ɨ-, pl. *χIop:-Vr 'sheep, sheep-flock' (collect.). This would be possible if we suppose a metathesis *χIop:Vr < *χIor-p:V in early PL, with a reanalysis of the original plural suffix *-p:(V) as a part of the root.
Notes: One of the cases with the interesting correspondence PEC *χHw : PWC *Łʷ. It is not yet clear what should be reconstructed in these cases: perhaps, some cluster like *χl- or *lχ-. It is also possible that in some cases PAT l- is a result of secondary lateralisation, and Ub. w : PAK *ħ could also point to PWC *χ́Iʷ (for which otherwise no examples are found). Most of the EC languages point to the PEC oblique base *χ_Hwĕj-rV- (cf. PN *pħare-, PA *χʷor-, PD *χ:ur-, PL *χ:ʷäjrV-); in some languages (Shakhdagh, Khin.) the former oblique base became direct. See Trubetzkoy 1930, 277, Abdokov 1983, 123.
Notes: The comparison is quite plausible phonetically and semantically. The only problem is the vowel -o- in PTsKh ( < PTs *-ɔ-); however, the word is attested only in Khvarsh. and Inkh., and thus a reconstruction of PTs *ɨ or *ǝ is also not absolutely excluded (a regular reflex would be PTs *χ:ɨr).