Comments:KW 342. The root is homonymous with *seɣül 'tail' (v. sub *si̯ū́bu), but certainly different historically; although now it is almost obsolete (but noted both in Lessing's and Ramstedt's dictionaries), it is certainly archaic. Mong. > Oroch sui(l), Nan. soịl, Neg. se(w)ul etc. (see ТМС 2, 120).
