An Etymological Dictionary of the German Language/Weiler
Weiler, m., ‘village, hamlet,’ from MidHG. wîler, m., ‘small farm, hamlet.’ OHG. wîlâri occurs only as the second component in compound names of places (e.g., Brûwîlâri, equiv. to Brauweiler). MidLat. vîllâre, ‘farm’ (Fr. villier), was adopted in local names, just like Lat. villa (OHG. -wíla, e.g., in Rotwíla, equiv. to Rotweil); comp. Fr. ville, ‘town.’ The word seems to have been borrowed contemporaneously with Weiher.