The common NC exclusive 1st person plural pronoun. Some languages have preserved traces of alternating stems *ži(-n) (dir.), *ža- (obl.), *ʔižV (gen.). [There may have also existed an ergative form *ʔež-, but since the Nakh languages, usually preserving the archaic ergative pronominal stems, have lost this pronoun, it can not be reconstructed.] In some languages (Lak., Ub., some Lezg. languages and Darg. dialects) this has become the only form of the 1st person plural pronoun (having superseded the old inclusive forms); in other languages (Nakh, Tsezian) the process was reversed and original exclusive forms were superseded by inclusive ones.
See Trubetzkoy 1930, 273. Abdokov (1983, 137) strangely enough compares the Ubykh form š́ǝ- with the PEC inclusive *Lǟ, which is quite impossible for phonetic reasons.