Owls hooted to one another in a disgruntled sort of way over the babble and the scraping of heavy trunks.
"Just have to find out for ourselves, then," said Ron, and they left Hagrid looking disgruntled and hurried off to the library.
There are no more uses of "disgruntled" in the book.
Show samples from other sources
The employees were disgruntled by their bad working conditions
But I’m disgruntled because six women have been here to say good-bye to me, and every one of the six managed to say something that seemed to take the color right out of life and leave it as gray and dismal and cheerless as a November morning.