A phrase used to describe action in various situations. Most commonly used to describe taking a hit from a bong or a joint, but can also be used to describe 'hitting' a bottle of booze. etc.
Also used to describe sexual activities.
The dankest of the dank, marijuana with a very high thc content (one hit quit shit is usually around 19-20% thc). Thus you don't need to smoke more than one hit to be really high.