An Etymological Dictionary of the German Language/Krabbe
Krabbe, f., ‘crab,’ borrowed, like most words with medial bb, from LG.; comp. MidLG. krabbe, Du. krab, AS. crabba, E. crab, Scand. krabbi; the strictly HG., i.e. permutated, form Krappe, appears in the 16th cent., yet the word was native only to the maritime Teutons. Krebs is from a cognate stem, but Gr. κάραβος, Lat. carabus, ‘sea-crab,’ are neither prim. allied, nor are they the forms from which the Teut. words were borrowed. Fr. crabe, ‘crabfish,’ is most closely connected with the Teut. and with the Lat. word.