An Etymological Dictionary of the German Language/Tölpel
Tölpel, m., ‘blockhead, booby,’ from MidHG. törpel, dörpel, properly dörper, dörpœre, m., ‘peasant, clownish person, blockhead’; really identical with Dörfer, ‘villager.’ MidHG. dörper is a MidG. and LG. form (for genuine MidHG. dorfœre). The LG. form of the MidHG. word is explained by the fact that Flanders, the medium by which French terms relating to the court and chivalry were introduced into Germany, also furnished some words (comp. Wappen) to HG.