I knew what "keuf" meant, but never how it got constructed. I learned the word because of an MC Solaar lyric... "Qui vole un oeuf, vole un boeuf. Qui viole une meuf se fait serrer par les keufs."

"meuf" was obvious to me but "keuf" never was.

So thank you! You've answered something I was wondering about for more than 20 years now.