Appeler un chat un chat

Literally: To call a cat a cat

Example: “Je vais appeler un chat un chat : ton projet ne tient pas la route.” — I'm going to call a spade a spade: your project doesn't hold up.

English equivalent: To call a spade a spade

Origin: Boileau made it famous in his first Satire of 1666 — j'appelle un chat un chat, et Rolet un fripon (I call a cat a cat, and Rolet a crook), Rolet being an actual, notoriously dishonest prosecutor of the day — but he was not the one who invented it. Erasmus has the same figure in Latin in 1530, ficus ficus, ligonem ligonem vocat (calling a fig a fig, a spade a spade), itself drawn from a Greek proverb Lucian records in the 1st century. Pierre Richelet's 1694 dictionary defines the sense plainly: to call things by their real name, with no dressing-up. A theory crediting the phrase with an old obscene double meaning does not hold up chronologically — Alfred Delvau's 1864 dictionary of slang only records that sense two centuries after Boileau.