An Etymological Dictionary of the German Language/Schreck
Schreck, m., ‘fright, terror, scare,’ from MidHG. schrëcke, m., allied to schrecken, vb., from MidHG. schrëcken, OHG. scrëcchôn, ‘to start up, spring up, spring, leap'; the early sense (comp. the evolution in meaning of sich entsetzen) is preserved in the compound Heuschrecke. From this vb. comes the causative schręcken, ‘to cause to spring up, terrify.’ In connection with the intensive form OHG. scrëcchón, comp. further OHG. scricch, MidHG. schric(ck), m., ‘starting up suddenly, fright'; Du. schrikken, ‘to frighten,’ Scand. skrika, ‘to glide.’ The root is essentially HG.