I did not have the foggiest idea what he meant.

我压根儿不知道他是什么意思。

《柯林斯英汉双解大词典》

I haven 't the foggiest idea what it is.

那是什么我根本就不知道。

youdao

I haven't the foggiest idea what you are talking about.

我一点也听不懂你们在谈些什么。

youdao

And that was with only the foggiest idea of what Arzoo was up to and before Bhatia was even looking for money.

FORBES: Just plain uppity

Second, Americans have only the foggiest understanding of how their data is being collected and what can be done to limit that collection.

FORBES: Move up http://i.forbesimg.com t Move down

This observation led to the theory that some mysterious, gravitationally repulsive dark energy must be behind the rising expansion of the cosmos - although we don't really have the foggiest idea what that is.

BBC: Dark discussion ahead for Europe and US