The act of hot boxing a car with marijuana smoke (multiple blunts is a very easy and preferred method) and then rolling down a window or opening a door next to an unknowing individual to unleash the fury of a potent THC fog. Thus, ganja bombing.
One of the greatest things about ganja bombing is seeing the victims reaction- each one is unique and hilarious.
stoner 1: "Okay, it's getting hard to see and breathe."
stoner 2: "Don't worry, I've spotted a victim."
stoner 1: *rolls down window*
stoner 2: "Oh shit, the smoke is still pouring out!"
stoner 1: "What a beautiful ganja bomb."