in confidence的意思是“私下地, 秘密地”，具体的说它有以下两个含义：
（1）秘密地
（2）推心置腹地,说心腹话.
in confidence的用法例句
I told you that in confidence so why did you tell Jean about it?
我是私下告诉你的,你怎么又告诉了琼呢?
Just in confidence,I'm going to tell you something that may surprise you.
推心置腹地说,我要告诉件让你吃惊的事情.
I understand that we speak together in confidence.
我明白，我们是在私下里交谈知心话”。
In the circumstances we'll tell you what we can, within limits, of course, and in confidence.
在这种情况下，我们会把能告诉你的都告诉你，当然这是有限度的，而且需要保密。
As for anything told to me in confidence, well, my lips are sealed.
至于私底下告诉我的任何事情，我会守口如瓶的。
I should like to exchange a few words with you in confidence.
我想私下和你交换点意见。
I am telling you this news in confidence.
我秘密地告诉你这个消息，不要外传。
I'll tell you in confidence why I'm worried.
我悄悄告诉你我为什么心烦。
A person who holds a hand over his mouth when he is talking is signaling that he is lacking in confidence.
一个人如果在谈话时总是用一只手捂着嘴，这就表明他缺乏自信。