Flash mobbing refers to the act of a group of people suddenly gathering in a public space to perform an unusual or seemingly spontaneous act, often for the purpose of entertainment or social commentary. There are several synonyms for flash mobbing, including "guerrilla performance," "spontaneous gathering," and "flash activity." Other similar terms include "pop-up event" and "instant event." While flash mobbing typically involves choreographed performances or stunts, these alternate terms encompass a broader range of impromptu events. However, the element of surprise and the spontaneity of these events remain a key characteristic of flash mobbing and its synonyms.