The duke embraced Sancho and told him he was heartily sorry he had given up the government so soon, but that he would see that he was provided with some other post on his estate less onerous and more profitable.
There are no more uses of "onerous" in the book.
Show samples from other sources
They argue that onerous regulation is driving business from the city.
My duties weren’t onerous; I only had to greet the guests.