Comments: PAT *cǝ (the pure root is preserved in Abkh. á-c, Bz. á-c 'fang'; the meaning 'tooth' is being rendered by the compound *pǝ-cǝ lit. "front tooth" > Abaz. pǝ-c or *qA-pǝ-cǝ lit. "head's front tooth" > Abkh. a-χa-pǝ́-c (Bz. with secondary voicing a-χa-bǝ́-c).
PAK *c:a. In Ub. the element -ḳ́ǝ is an original singularity marker.