牛津電影裡 65%
在內心深處;在心底
if you know sth deep down, you know your true feelings about sth, although you may not admit them to yourself
Deep down, you know I'm right.
牛津電影裡 35%
本質上;實際上;事實上
if sth is true deep down, it is really like that, although it may not be obvious to people
Deep down, he's all fluff.
釋義來自《牛津高階英漢雙解詞典》第 9 版