Comments:A Western isogloss. The medial cluster with *-b- should be reconstructed in order to account for labialization in Turk. and Mong. However, the Turkic form may be alternatively compared with Mong. ojun 'thought' - if the latter is not related to PT *ōd 'thought' (as suggested by Владимирцов 285 and supported in Мудрак Дисс. 103).