in secret idiom
B2 秘密地，暗地里
in a private place with no one else present and without other people knowing
The negotiators were meeting in secret for several months before the peace agreement was made public. 在和平协议公布以前，谈判秘密地进行了几个月。
在内心里；在脑海里
only in someone's thoughts, without telling other people
He says he loathes her, but I think in secret he really likes her. 他说他恨她，但我认为他心里其实是喜欢她的。