Comments: PAT *pǝśǝ- (cf. also Bz. a-pśǝʒ, Ashkh. psǝz). Both in Abkh. and Abaz. the root is present in compounds with unclear second components (-ʒ in Abkh., -lačʷa in Abaz.).
PAK *p:c:a : the pure root has meant 'big fish'; most common is the diminutive derivate *p:c:a-źájǝ (Ad. pcaźǝj, Kab. bʒaźej).
We have to reconstruct initial *p: to account for the AK progressive assimilation (*p:c:a < *p:sa); both in PAT and Ub. the assimilation had been regressive. Numerous attempts to analise the word on WC ground and to explain it as an IE loan (see Shagirov 1, 82 with literature) seem to us unsuccessful.