This is the 8916th most frequent German word.
langeweiler
"Boring person" or "bore."
In this sentence, 'Langeweiler' is used as a noun to describe a person who is boring.
Er ist wirklich ein Langeweiler, weil er immer nur von den gleichen Sachen redet.
He is really a bore because he always talks about the same things.
Here, 'Langeweiler' is used metaphorically to describe the book as being boring.
Das Buch war ein richtiger Langeweiler, ich konnte kaum das Ende abwarten.
The book was a real bore; I could hardly wait for it to end.
In this context, 'Langeweiler' is used to describe people's personalities, emphasizing the lack of boring individuals at the party.