PAT *žʷa (cf. also Bzyb. ž̌a-bá); PAK *ṗć̣ǝ. A complicated case. PAK *ṗć̣ǝ can only go back to PWC *P-ć̣ʷǝ (a form which obviously corresponds to EC, see Trubetzkoy 1930, 82). The Ubykh form can go back to a voiced variant *źʷǝ; but the PAT form needs a more complicated explanation, if it belongs here at all: it may also reflect a secondarily voiced PWC variant *(b)-ʒ́ʷV > PAT *ža, with labialisation under the influence of PAT *zʷǝ 'nine' (*ža > *žʷa ).
The hypothesis of uniting all three forms (PAT, PAK and Ub.) belongs to Abdokov (1973, 66). One can either accept it (with the complicated explanation presented above), or else separate the Ub. and Abkh. forms under a distinct protoform, PWC *ž́ʷV (since *ž́ʷ regularly gives PAT *žʷ and Ub. žʷ). However, Shagirov's attempt to unite Abkh. ž̌-ba 'nine' and ž̌a-ba 'ten' (Shagirov 1, 80-81) is certainly untenable: in the Bzyb. dialect they are opposed as ź̌-ba vs. ž̌-ba and go back to different PAT forms (*zʷǝ and *žʷa respectively).