Комментарии:KW 107. A Western isogloss. All forms reflect a morphological derivative *tagi-gu(r/l) (which explains both labialization in the second syllable and front row in Mong.). The Turkic form deserves special comment: Ramstedt 1924 derived it from *tüke- `be exhausted' (see under *t`ukì), i.e. "being exhausted, having come to an end" = "is not". The semantic derivation seems quite probable, but PT *degül is phonetically not derivable from *tüke-; it appears rather to be derived from an otherwise unattested PT *degü- < PA *tagi, but with the same semantic shift. There is yet another possibility available: regarding -(ü)l in Turkic as a remnant of the negative particle = PM *ülü `not', i.e. *degül = "not filled, incomplete".