An Etymological Dictionary of the German Language/Annotated/hapern

by Friedrich Kluge

hapern, verb, ‘to stick, hitch,’ formed from Dutch (Middle Dutch) haperen, ‘to miss, stutter’; yet also Suabian hăperen (as well as Swiss hâpen, ‘to crawl’?). The corresponding terms, origin, and history of the diffusion of the cognates are obscure.