An Etymological Dictionary of the German Language/wichern
wichern, vb., ‘to neigh, shout noisily,’ an intensive form of the equiv. MidHG. wihen (wihenen, wihelen), OHG. wihôn for *wĭjôn, *hwĭjôn; formed from the same root as MidHG. weijen, OHG. weiôn (hweiôn), ‘to neigh’ (E. dial. to wicker). With the onomatopoetic root hwī̆ are connected, though with a different evolution of meaning, AS. hwînan, E. to whine, OIc. hvîna, ‘to rustle, drink (of beasts).’