An Etymological Dictionary of the German Language/Lünse
Lünse, f., ‘linch-pin,’ from the equiv. late MidHG. luns, lunse; comp. OSax. lunisa, Du. luns, lens. In OHG. lun, luna, MidHG. lun, lune, f., also OHG. luning, MidHG. lüninc, lüner, ‘lungs’; comp. AS. lynes, m., E. linch-pin (Goth. *lunisi is wanting); it may have been formed like Goth. aqizi, jukuzi. Some etymologists connect these cognates with the Aryan root lu, ‘to loosen,’ discussed under verlieren, so that Lünse is lit. ‘peg for loosening the wheel.’ Comp. further AS. âlynnan, ‘to release.’