Comments:АПиПЯЯ 68, 280, Дыбо 13. In Jpn. 'thin' < 'pressed, compressed'. The root is actively interacting with *pĭ̀sa and *p`i̯úsa q. v. The vowel variation in Japanese dialects may point to a variant *pằse.
Comments:The root should be distinguished from *bašo q. v. (cf. the distinction in Manchu), although some contaminations were possible. Note a peculiar alternation *-s-/*-č- both in TM and Kor., possibly indicating an old suffixed variant *p`asi-č`V. PJ *pasir- 'run', because of its vocalism, is rather to be attributed to PA *p`ĕ̀ĺo q. v.