Usage:
1. In modern times, people's first impression of Erdan is a person's name, which generally refers to the boys whose elder brother ranks second in the family, such as Wang Erdan and Li Erdan.
2. People's nicknames. Parents usually buy them for their children. The meaner the nickname, the better life! This is usually a custom in remote areas.
3. Sometimes describing a person's stupidity means honesty and honesty.
4. Nicknames for friends in life, such as double-egg classmates in university dormitories.