An Etymological Dictionary of the German Language/Ritten

by Friedrich Kluge

Ritten, m., ‘fever,’ from the equiv. MidHG. rite, ritte, OHG. rito, ritto, m., for an earlier *hriþjo, ‘fever’; so too AS. hriþa, m., ‘fever’; allied to OHG. rîdon, MidHG. rîden, ‘to shiver,’ AS. hriþian, ‘to shiver in a fever,’ OHG. rîdo, ‘shivering,’ AS. hriþ, ‘storm.’ The root hrī̆þ, pre-Teut. krī̆t, ‘to move wildly,’ appears also in OIr. crith, ‘shivering.’