Comments:KW 69, Владимирцов 361, Poppe 21, 81, Новикова 1972, 117. In Jpn. we have to assume a secondary vocalic development in a long word: *pútí-(u)si > *pítú(n)si (the word is most probably a compound with *úsí 'cow' in the second part, cf. the Korean match).