well attended
adjective uk/ˌwel əˈten.dɪd/ us/ˌwel əˈten.dɪd/
有很多人参加的
If an event is well attended, many people are present at it.
[ before noun ] The information was given at an unusually well-attended press conference yesterday. 这个消息是在昨天举行的新闻发布会上宣布的，与会者甚多，出乎意料。