When someone is out of the loop, he or she is not being an insider of a group that is kept up-to-date with information about something. loop的本意是指“圈，环”，out of the loop“在圈子之外”，表示某些人对发生的事情或者小道消息不甚了解。它的反义词则为in the loop.

Examples：
I haven’t heard anything. I am out of the loop on that project. 我没有听到任何消息。我对该项目一无所知。
I didn’t know Jack is leaving, I was out of the loop on that one. 我不知道杰克要走了，我对这个事情完全不知情。