What do you mean, become sworn?

Sworn brothers/sisters

In the old social communication custom in China, people who are not related by blood become brothers and sisters, and individuals or groups with the same interests kowtow, exchange jobs, drink blood wine and swear to heaven, and bind and safeguard the same interests with the same beliefs and vows.

People who are unrelated to each other meet as equal brothers and sisters because of deep feelings or the same purpose, and are called "Yi Di", "Yi Di", "Yi Mei" and "Yi Jie". Nowadays, the northern areas are often called "blood brothers", "blood brothers", "blood sisters" and "blood sisters". The younger generation is "adopted son" and "adopted daughter", and now most of the northern regions are called "adopted son" and "adopted daughter"; The elders are "adoptive father" and "adoptive mother", and now they are mostly called "michel platini" and "adoptive mother" in northern China, and they are godmothers.

Qing Wu's "Twenty Years of Wonderland" is the twenty-third time: "When you talk about becoming sworn, I will tell you a joke." Example: Pu's "Evil Flower" replied 19: "Our old man sent a letter to the general manager, and it really was him." Usage: as object and attribute; Used for correspondence and other synonyms: Yi Jie Jin Lan quotes antonym: Dear John.