An Etymological Dictionary of the German Language/Annotated/-falt
-falt, -fältig, adjective suffix, ‘-fold,’ from Middle High German -valt, Old High German falt; compare Gothic -falþs, Anglo-Saxon -feald, English -fold, Old Icelandic -faldr; a common Teutonic suffix in the formation of multiplicatives; it corresponds to Greek πλάσιος in δι-πλάσιος, &c. (also δίπαλτος, ‘twofold’), for pltios, with which -falt seems to be primitively cognate. See falten, and Einfalt under ein.