The meeting was held in secret.

会议是秘密召开的。

《牛津词典》

Dan found out that I had been meeting my ex-boyfriend in secret.

丹发现了我一直和前男友秘密见面。

《柯林斯英汉双解大词典》

Can you make a novel, as he says in the essay, that will "sprout wings and grow claws" in secret in his mind?

就像他在文章里说的那样，你能够让一本小说在他脑海里秘密地“展开翅膀，伸出爪子”？

youdao

However,these musicians often sing in secret and their music is not widely known.

VOA: special.2009.11.25

He wrote -- and this too is in the packet -- he wrote: Listen, Diodati, but in secret lest thy blush, and let me talk to you grandiloquently for a while.

他写道--这也在阅读材料里--他写道：,听着，迪奥达蒂，但要悄悄的，以免你会脸红，让我对你说说大话。

耶鲁公开课 - 弥尔顿课程节选

I guess, like, there're certain things like in the meetings that are secret, like the ritual or whatever,

我想有一些事情是秘密的，例如会议程序什么的，

耶鲁对比哈佛 - SpeakingMax英语口语达人

The deal was negotiated hastily and in secret by a clutch of senior administration officials.

ECONOMIST: Diplomacy and proliferation

The deals are arranged by placement agents in secret and only registered after the fact.

FORBES: Piped Aboard

The parents decorated the tree in secret, placed the gifts, and lit the real candles.

CNN: Celebrating with the Christkind