Stonkered

[…] she ate heartily, demolishing two helpings of very grey roast lamb and only announcing herself stonkered after scraping clean the large monogrammed plate of steamed pudding.

Mrs. Moreland was not often at a loss, but this time she felt completely stymied or stonkered – a word to whose derivation we have no clue and perhaps it isn't a real word, but we have always known it. Perhaps – if it is a real word – it comes from Golf, a language of which we are completely ignorant.