Definition
To have absolutely no knowledge or understanding of a particular subject.
對某事完全不了解，一無所知。
I don't know the first thing about the stock market, so I'm afraid to invest.
我對股票市場一無所知，所以不敢投資。
She doesn't know the first thing about computer programming, so she needs to ask for help.
她對電腦程式設計一無所知，所以需要尋求幫助。
When it comes to cooking, I really don't know the first thing, I always mess things up.
說到烹飪，我真的是一竅不通，總是搞砸。