Meaning:

    “反” means “against, opposite,” and “水” means “water.” This term refers to the action of betraying one’s own team and turning to help the enemies or failing to keep one’s commitment. Still in use today, the phrase originated from the ancient times in China. During the Spring and Autumn Period, in the State of Jin, two of the three allies turned against the third one in the battle of Jinyang by flooding their ally’s army camps with river water. The three winners redivided the country after the battle, and therefore came the term “反水.”

    Example:

    A: 你的房子买了吗？

    Nǐ de fángzi mǎi le ma?

    Did you buy that apartment?

    B: 没买成，卖家反水了要涨价。

    Méi mǎi chéng, màijiā fǎnshuǐ le yào zhǎngjià。

    No, I didn’t. The seller failed to honor the deal and wanted to hike the price.