In English, the word "疑惑" can be translated as "doubt" or "confusion". This word comes from the Old French word "doute" and the Latin word "dubitare", both of which mean "to doubt".

Here are some examples of "doubt" or "confusion" in English:

I have doubts about the validity of his argument. (我对他的论点的正确性有疑惑。)

She looked confused and didn't know what to say. (她看起来很困惑，不知道该说什么。)

He expressed his doubts about the project's feasibility. (他对该项目的可行性表示疑惑。)

The situation was so complicated that it caused confusion among the team. (情况非常复杂，引起了团队内的疑惑。)