To deliver a massive blow to male genitals, usually done with a clenched fist in an upper-cut fashion. This move is reserved for those who have committed a grevious violation of male protocol (aka breaking "the guy code") and should only be deployed as a last resort.
"The guy sucker punched me after I told him to leave my girlfriend alone, so I gave him the Rouchambeau. That settled that."
the act of settling a point of contention by alternating punches or kicks of each other's testicles until one participant yields.
I'll take these two, you take those two, and then we'll rouchambeau for the last.