From shiyth; the seat (of the person) -- buttock.
see HEBREW shiyth
H8357. shethah
III. שֵׁת noun [masculine] seat (of body), buttocks (compare Late Hebrew שִׁית, Aramaic foundation; compare [שָׁת] p. 1011; NöM 98); — absolute ׳שׁ Isaiah 20:4; plural suffix שְׁתוֺתֵיהֶם 2 Samuel 10:4.
III. שׁתה (√ of following; Aramaic שְׁתִי, weave (Judges 16:13 ᵑ6 ᵑ7); textura; compare Arabic , , set the warp).