Gathering a large group of people and barging into a friend's house unannounced, then being very loud, rude, disruptive, or just plain out destructive.

To stay up, or not sleep to gain a sense of altered reality, because you can't sleep anyway or don't have any money for grog or whatever.

The sensation felt on ones prosterior when putting on a new pair of underwear.

The act of stealing items from a merchant or street vendor with many people simultaneously running up, grabbing whatever they can and then running off. It has to be done together so that the merchant doesn't know who to try and stop.

The sensation that you get on your prosterior when you put on a warm pair of boxers or underwear.

To be jostled or hustled to move you, or get rid of you, or get you to do something that someone wants you to do - that you don't necessarily want to do.

the incidence of a man being anal rape mostly in prison
bum rushing usually ends in one or both members deficating