Ceppa

It is the tip of the cock, in roman slang.

It is used in a particular expression:
"na ceppa de cazzo"
that literally means:
"a tip of cock"
But it is generally used to say: "no way"
and like every italian expression, it has a proper move that gives it more sense, and it is a genital shaking with the hand

fonetics: nà c'éppà dé kàzzó