The act of ejaculating on someones dvd copy of either of the two Scooby Doo Movies and then screaming zoinks at the top of your lungs.
Shaggy was beating off a nutt in the mystery machine right onto a dvd copy of Scooby Doo 2 : Monsters Unleashed.
The rest of the gang could hear zoinks being screamed from inside the house.
Therefor Shaggy was Zoinking.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.