フラッシュモブ

noun

flash mob

A group of people who suddenly assemble in a public place, perform an unusual act, and then quickly disperse. Often organized via social media or text messages.

• 駅えき前まえで突とつ然ぜんフラッシュモブが始はじまった。

  A flash mob suddenly started in front of the station.

• 彼かれらはSNSでフラッシュモブの計けい画かくを立たてた。

  They planned a flash mob via social media.