a.

1. 前进的；进行的；不间断的
   The Japanese aggression of China has been ongoing for several decades.

   日本对中国的侵略已经持续了好几十年了。

   It is very impolite to interrupt the ongoing conversation of other people.

   打断别人在进行中的谈话是不礼貌的。

n.

1. 前进
2. （常复数）举止；事态

adj.