An Etymological Dictionary of the German Language/scheißen
scheißen, vb., ‘to go to stool, excrete,’ from MidHG. schîȥen, OHG. scîȥan; corresponding to the equiv. Du. schijten, AS. sčîtan, E. to shit, OIc. skíta. The common Teut. root skī̆t, ‘to excrete,’ is probably connected with the Aryan skhī̆d, discussed under scheiden; its lit. meaning is perhaps ‘to dissever’?. From the Teut. cognates are derived Ital. (dial.) scito, ‘excrement,’ and OFr. eschiter.