"Gou Wei Xu Diao" literally means using a dog's tail to continue a marten fur, a metaphor for appending something inferior to something precious, creating a glaring mismatch. This idiom comes from the Book of Jin: Biography of Prince Zhao of Lun. At that time, after Prince Sima Lun of Zhao usurped the throne, he indiscriminately granted official titles and ranks, causing a shortage of marten-tail ornaments for court officials' caps, so dog tails were used as substitutes. Hence the folk satire went, "When marten is insufficient, dog tail continues." Later, this idiom was often used to criticize the practice of substituting inferior goods for good ones, especially in literature and artistic creation, referring to later parts being far inferior to earlier ones and ruining the overall beauty and value. It carries a clearly derogatory connotation, expressing regret or mockery toward declining quality and mismatched before-and-after elements. It is mostly used to evaluate works, events, or personnel arrangements, emphasizing the huge gap between later content and earlier excellent parts, reminding people to maintain standards and not pad things out with inferior substitutes.
📝 Example
1. The first half of this movie is absolutely brilliant, but unfortunately the second half has a dragging plot and chaotic logic—it's simply a dog's tail continued with a marten's fur. (A metaphor meaning that the subsequent part is far inferior to the earlier part and ruins the overall quality.)
2. He originally wrote an excellent paper, but added several irrelevant paragraphs just to meet the word count, which turned out to be a dog's tail continued with a marten's fur. (A metaphor meaning that inferior content is appended to an excellent work, making it seem incongruous.)