Idiom: fall head over heels in love (with someone)

Meaning: to fall deeply in love with someone, especially suddenly.

意为“坠入爱河”。

Head over heels 本身是指“颠倒，完全地，从头到脚”，形容一个人整个身体倒下去的样子，fall head over heels in love 则用来形容一个人完全被另一个人所迷住，疯狂恋爱，堕入爱河。

Example：

1. He fell head over heels in love with her.
他与她沉溺情海，爱得晕头转向。

2. I fell head over heels in love with her the moment I saw her．
我第一眼就不顾一切地爱上了她。