The French saying “mettre de l’eau dans son vin” means literally “to put some water in one’s wine.” It means to be less ambitious, to moderate one’s claims or to moderate one’s demands.

It comes from the practice of moderating the intensity of wine by adding water to it.

The expression dates back at least to the middle of the 16th century.

Equivalent English expressions include “to eat humble pie,” “to lower one’s sights,” and “to tone it down.”