To occur or take place.
Let me tell you how it happened.
To happen to; to befall.
(with infinitive) To do or occur by chance or unexpectedly.
Do you happen to have an umbrella?
(followed by on or upon) To encounter by chance.
(of a place) Busy, lively; vibrant, dynamic; fashionable.
This is a happening place tonight!
(of a person or product) Trendy, up-to-the-minute.
He is a real happening guy.
Something that happens.
A spontaneous or improvised event, especially one that involves audience participation.