Meaning:

This term, first used by Douyin users, refers to “disco dance.” It originated from a piece of popular disco music titled “Bow Chi Bow,” written by duo Peter Garnefski and Ferry Ridderhof. In the climax of that piece when the words “bow chi bow” are sung, that part sounds very similar to the Chinese pronunciation of “857,” which has given rise to the funny reference. Some also say it refers to night clubs, as some people brag that they hang out at night clubs from 8 p.m. to 5 a.m., seven days a week.

Example:

A: 你周末出门玩儿了吗？

Nǐ zhōumò chūmén wán r le ma？

Did you go out and have fun this weekend?

B:周六晚上和几个同学去857了。

Zhōuliù wǎnshang hé jǐge tóngxué qù bāwǔqī le。

I went with several classmates to dance disco on Saturday night.