A denominative from shesh; to sixth or divide into sixths -- give the sixth participle
see HEBREW shesh
H8341. shishshah
[שִׁשָּׁה] verb Pi`el denominative give sixth part of (si vera lectio); — Perfect2masculine plural consecutive הָאֵיפָה וְשִׁשִּׁיתֶם Ezekiel 45:13 (+מִן particle), but < read שִׁשִּׁית Vrss and modern ("" שִׁשִּׁית va). — וְשִׁשֵּׁאתִיךָ 39:2 see שׁשׁא.