French slang has a rule: flip the syllables and hide the word in plain sight

Verlan is a French word game that disguises ordinary words by inverting their syllables - 'femme' (woman) becomes 'meuf', 'louche' (shady) becomes 'chelou'. It grew out of working-class and immigrant neighborhoods as a way to speak without being fully understood by outsiders. Some verlan words have since slipped so completely into mainstream French that most speakers no longer notice they're backwards.

— Natalie J. Lefkowitz, Talking Backwards, Looking Forwards: The French Language Game Verlan — Gunter Narr Verlag, 1991
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