An Etymological Dictionary of the German Language/Annotated/Krampf
Krampf, masculine, ‘cramp, spasm, convulsion,’ from the equivalent Middle High German and Old High German krampf (Old High German also chrampfo); compare Old Saxon cramp, Dutch kramp, feminine, English cramp; the common West Teutonic term for ‘cramp’; originally an adjectival substantive from Old High German chrampf, ‘curved,’ Old Icelandic krappr (normal for *krampr), ‘narrow, pressed close.’ The Teutonic stem krampa- has numerous cognates in German; besides the Low German loan-words krampe, krämpe, krämpel, we may mention Old High German chrampf, ‘hook, border,’ chrimpfan, Middle High German krimpfen, ‘to contract in a crooked or spasmodic fashion,’ Middle High German krimpf, adjective, ‘crooked’ masculine substantive ‘cramp’; Modern High German krumm is also allied, as is indicated by its Old High German and Middle High German variant krumpf, ‘bent, twisted.’ Compare krumm, and Old High German chrimpfan, Middle High German krimpfen, ‘to be convulsed,’ Modern Dutch krimpen, ‘to draw in, shrivel,’ Middle English crimpil, ‘wrinkle,’ crumbe, ‘hook,’ crumpe, ‘crump,’ English to crimple, ‘to contract,’ &c.; Old Icelandic krappr, ‘narrow,’ and its nominal verb kreppa, ‘to compress.’ Compare Krüppel and Krapfen.