gravity hit 

A hit of pot smoke taken from a gravity bong. These are generally high-volume inhalations (2 litres to 1 gallon, usually) and yeild large quantities of smoke, usually resulting in excessive coughing.

One gravity hit of medium potency pot is usually enough to get fairly stoned.

I must have smoked a half gram in that one gravity hit. It blew my head off, now I'm pretty baked.

gravity hit by Experienced Smoker April 16, 2007

gravity hit 

taking a toke and holding it in while hanging upside down by your knees from the monkey bars

best to use a spotter so ya don't crack ya head open

That was a good gravity hit,totally sweet head rush now hand me the beer bong.

gravity hit by the bomb December 7, 2003