I also checked a lot of information and found that the saying "meat in the steamed bun" basically has no exact origin. However, a lot of information has some similar views, so I will summarize it here and put forward my opinions on some doubts. Both Mu Yu and Mu Longyuan proposed treating "jiamo" as one word, but here in Xi'an, the steamed bun used for "clipping" has its original name, which is "Baiji steamed bun". [2] It should be an omission of "Roujia Mo". Of course, there is also the term "Roujia Mo", but it usually refers to "Roujia Mo", which is the omission of "Roujia Mo". @北海 also pointed out that the reason why the Baiji Mo is called "Jia Mo" is because it is filled with meat and vegetables. I think this makes sense. But I think the development process is still the result of "omission". I will describe this point of view in detail. When Bai Ji Mo started to be stuffed with meat and vegetables, these foods might have been named meat buns, vegetable buns, flower stem buns, etc. among the people. However, if a certain store only sells one kind of buns, Depending on the development of language, people may be accustomed to "omitting" and would say "a jiamo" or even simpler, "one". We often say this nowadays, right? If there is no ambiguity, more people will omit some words from the name of the food, or even omit it completely. So in terms of development, it is very likely that the original name of Roujiamo was "Roujiamo", and after a long process of omission, it became "Roujiamo". To sum up, I still think this is a folk omission, but in terms of part of speech, "Jiamo" should not be regarded as one word. In this case, which is more difficult to verify, individuals tend to think of it as a local characteristic, so why is there such an answer as "2B version". I think "Roujiamo", a name that is ungrammatical but widely used by the people, may be more of a "convention" in language development. [3] Such examples should still be seen in various parts of the north and south of my country. There are some (well... I haven't thought about the specific examples. In view of this thinking about "Roujiamo", there may be some names that the locals can use to make it more accurate. Friends are welcome to suggest it~). [2] The answer with the most approval only cited examples that are consistent with the theory he proposed, and did not cite some possible special cases, so I think it is incorrect.