不知所措 (bù zhī suǒ cuò) is a Chinese expression that means "to be at a loss" or "to be at a disadvantage" and is often used to describe a person who is unsure of what to do in a given situation.

The literal translation of 不知所措 is "not know where to start," and it comes from the Chinese idiom 不知所措, which literally means "to not know where to put one's hands or feet."

Some examples of 不知所措 in English are:

"I was at a loss for words when I saw the accident."

"She felt at a disadvantage when she had to give a presentation without any preparation."

In Chinese, these sentences would be:

"看到事故后，我不知所措。"

"她在没有准备的情况下演讲，感到不知所措。"