Comments:KW 291, ОСНЯ 2, 104, АПиПЯЯ 70, 97, 102, 278, Martin 234, Лексика 356. The Mong. form may belong here if *očkin < *očikin < *oti-kin; however, it may also reflect PA *p`ṑči 'spark' q. v. Korean has a frequent loss of initial vowel. Tone in Jpn. is irregular.