1. In an unguarded moment, he gave away most important secrets.
    他一不留神泄露了非常重要的秘密。

1.

1. 不小心的：unguard 无防备 | unguarded 不小心的 | unguardedly 不留神地

2. unguarded的翻译

2. 不谨慎的：ungrouped scores 未分组分数 | unguarded 不谨慎的 | unhackneyed 不平凡的

3. 不留神的,没有防备的：unguarded 不留神的,没有防备的 | secluded 隐遁的、隔绝的 | exceed 超过,胜过;超出

4. 大意的：unguarded 不留神的 | unguarded 大意的 | unguardedly 没防备地

1. 没有防备的；无人看管的
    If something is unguarded, nobody is protecting it or looking after it.

    e.g. I should not leave my briefcase and camera bag unguarded.
           我不该把我的公文包和相机包留在那儿无人看管。

2. 轻率的；不留神的
    If you do or say something in an unguarded moment, you do or say it carelessly and without thinking, especially when it is something that you did not want anyone to see or know.

    e.g. The photographers managed to capture Jane in an unguarded moment...
           摄影师抓拍到了简不经意的瞬间。
    e.g. He was ambushed by a reporter into an unguarded comment.
           他一不小心被记者套出话来。

1. displaying or feeling no wariness

    e.g. an unguarded remark

2. lacking protection or a guard

    e.g. an unguarded gate
           his unguarded queen was open to attack