1
- an event or occurrence（发生的）事情, 事件：
altogether it was an eerie happening.
总而言之, 这是一件非常怪异的事情。
2
- a partly improvised or spontaneous piece of theatrical or other artistic performance, typically involving audience participation半即兴表演（一种自发的半即兴演出, 常有观众参与）：
a multimedia happening.
一次利用多媒体的即兴表演。
- informal fashionable; trendy〈非正式〉流行的, 时髦的, 时尚的：
nightclubs for the young are the happening thing.
以年轻人为服务对象的夜总会是最近的时尚。