Proto-Altaic: *sòmú (~ z-)
Meaning: gore, gusset
Russian meaning: клин в одежде, ластовица
Comments: The original meaning was probably 'inner angle in a robe' (hence 'right lap' in Mong. and 'sleeve' in Kor.), with a generalization ( > 'inner angle') in Japanese; the TM match is semantically plausible (a further development 'gusset' > 'fish fin'), but very scantily attested and thus dubious.
