The longest-word in the Dutch-language?
Not sure, but Hottentottententenbouwtentoon stellingsterreinafsluitingsmaterialen voorraads verzendingskosten berekeningsstatenadministratie boekhoudkundigen has to come close. (Without the spaces, I added the spaces because the site automatically shortened it.) And it absolutely makes no sense and it means nothing. It just a funny 'word'.