An Etymological Dictionary of the German Language/Annotated/Brocke

Brocke, Brocken, masculine, ‘crumb,’ from the equivalent Middle High German brocke, Old High German broccho, masculine; Gothic *brukka, masculine, for which gabruka, feminine, occurs : formed by gradation from brechen (compare Trotte from treten); derivatives bröckeln, bröckelig.