单词when-least-expected
A logic error in a program that manifests itself only under certain conditions, usually when least expected or desired.
程序中的逻辑错误，这种错误通常是最不期待或最不情愿的特定情况下才出现的。
Inspiration means that an idea strikes when least expected.
所谓灵感，就是在不经意间，意趣袭来
Be careful of another"s feelings. Wit and humor at the other person"s expense are rarely worth it and may hurt when least expected.
照顾他人的感受。以损害他人为代价的风趣和幽默很不值得，你可能受到最意料不到的伤害。
This means that it can fail when least expected.
这意味着它可能在你最想不到的时候出差错。