Meaning:
This is the Chinese translation for the English term “flash mob,” which refers to a group of people who assemble suddenly in a public place, perform an unusual and seemingly pointless act for a brief time, then quickly disperse, often for the purposes of entertainment, satire, and artistic expression. Flash mobs are organized via telecommunications, social media, or viral emails. The term, coined in 2003, is generally not applied to events and performances organized for the purposes of politics (such as protests), commercial advertisement, publicity stunts that involve public relation firms, or paid professionals. In these cases of a planned purpose for the social activity in question, the term smart mobs is often applied instead. The Chinese occurrence of flash mobs was no later than in 2008.
Example:
A: 怎么公司门口忽然来了一群人跳舞？
Zěnme gōngsī ménkǒu hūrán lái le yīqúnrén tiàowǔ?
Why are a group of people suddenly dancing in front of our office building?
B: 是个快闪，好像是一个小伙子为了向女友求婚组织的。
Shì gè kuàishǎn, hǎoxiàng shì yīgè xiǎohuǒzi wèile xiàng nǚyǒu qíuhūn zǔzhī de。
It’s a flash mob, reportedly organized by some guy to propose to his girlfriend.
(Edited by Stephanie Yang)