dessaler

Literally to remove salt — used in cooking for pulling excess salt out of preserved fish or meat by soaking it (dessaler la morue), and on an industrial scale for desalinating seawater (dessaler l'eau de mer). Informally, se dessaler also means to lose one's naivety and become more worldly, a sense going back to 19th-century sailors' slang.

• Il faut dessaler la morue pendant vingt-quatre heures avant de la cuisiner. — The salt cod needs to be desalted for twenty-four hours before cooking.
• L'usine dessale l'eau de mer pour la rendre potable. — The plant desalinates seawater to make it drinkable.
• Depuis son voyage, il s'est bien dessalé. — Since his trip, he's become a lot more worldly.

Don't assume se dessaler always means the informal 'become worldly' sense — context matters, since it can also just mean a food item is losing its salt content (le poisson se dessale dans l'eau).