Comments:АПиПЯЯ 77, Rozycki 124. Tungus forms may be borrowed from Mong. (see Poppe 1966, 194, Doerfer MT 80). Medial *-j- has to be reconstructed, as in a number of other cases, to explain Mong. -b- (not -ɣ-) and Jpn. *-w- (not -p-); exceptional back vowel in Turkic may be also due to dissimilation with the medial *-j-. In Turkic one has to suppose a semantic development 'thin' < 'lean, weak' (the latter meaning is actually widely attested since the earliest texts).