n : A homemade smoking device that is made by a three liter bottle that is cut off at the bottom and uses a foil for the bowl. It usually work by putting marijuana in the bowl and the user lifts up the bottle and collects smoke and then the user takes the foil off and pushes his head in the water with the bottle making him have a really big hit.
The best way to make a gravity bong is by using a one gallon jug and a trambone mouth piece on the top of the jug then cut the bottom and use a big kitchen pot for the water.
Joint Masta Jay
Damn! I sure got a big hit from the gravity bong. That shit got me stoned in one hit!