The way in which douches deduce info and come to decisions. For example they must dedouche whether or not to spike a girls drink, join a fraternity, spike their hair, or wear a extra small shirt as an adult male.
He has the dumb look on his face because he can't dedouche which Nickelback cd to buy.
Someone of french origin who is, without any hint of a doubt, a douche.
"Look at that frenchy fag. What a douch."
"Yeah, man, He's Dedouche."