An Etymological Dictionary of the German Language/Annotated/Kropf
Kropf, masculine, from the equivalent Middle High German and Old High German kropf, masculine, ‘goitre, crop, craw’; corresponding to Dutch krop, masculine, ‘crop, bosom, bow of a ship,’ English crop (of birds, top, harvest), Anglo-Saxon cropp, which has the special meanings ‘crop, summit, top (of trees), ear (of corn, cluster of grapes’; Old Icelandic kroppr, ‘trunk, body’ (also ‘hump’), is still more remarkable. To these numerous senses, a primary meaning, ‘a round mass in the shape of a ball, a projecting spherical body,’ has been assigned; with this the Romance loan-words such as French groupe, ‘group, cluster, knot,’ coincide. Gothic *kruppa- might be related to Greek γρῦπός, ‘curved,’ if ‘crop, excrescence,’ represented the primary meaning of the group.