An Etymological Dictionary of the German Language/Annotated/Rachen
Rachen, masculine, ‘throat, jaws, abyss,’ from the equivalent Middle High German rache, Old High German rahho, masculine, for the earlier *hrahho; compare Anglo-Saxon hraca, masculine, ‘throat,’ perhaps also Anglo-Saxon hracca, ‘back of the head, nape,’ English rack, ‘neck of mutton’; also Dutch raak, ‘back part of the palate, inner parts of the month.’ Further references for determining the origin of the word are wanting; no relation to Kragen is possible.