Notes: Reconstructed for the PEC level. The combination with -w- is reconstructed to account for the labialised vowel in PN and PD; it also explains a specific behaviour of -r- (as if it were in a cluster with a laryngeal).
Abdokov (1983, 75) tries to connect the root with PAK *sakʷǝ 'mane' (q.v.), which is hardly justified.