What is the meaning of Happening?

present participle and gerund of happen

Busy, lively; vibrant, dynamic; fashionable.

Trendy, up-to-the-minute.

Something that happens.

A spontaneous or improvised event, especially one that involves audience participation.

happening (event)

happening

happening (spontaneous or improvised event, especially one that involves audience participation)

happening (spontaneous or improvised event)

happening

Source: wiktionary.org