An Etymological Dictionary of the German Language/Annotated/Scharbock
Scharbock, masculine, ‘scurf, scurvy,’ early Modern High German, a corruption of Middle Latin scorbûtus. From the same source are derived the equivalent Dutch scheurbuik, English scurvy, Italian scorbuto, and French scorbut. The ultimate source of the cognates is Dutch scheurbuik, or rather its older forms with a dental in the suffix, as in scorbutus (Dutch scheur, ‘rift, cleft,’ but, ‘bone’); Modern Dutch scheurbuik is also very probably a corruption, the word being connected with buik, ‘belly.’