Noun: A time when bros come together (traditional Thursdays) to get good and weekday drunk for no particular reason. A weekly tradition that dates back to 2006.
Used as a Verb: Beasting
Noun:
Your Slam Piece: "Hey, do you want to go to dinner at my parents house tonight and meet my sisters new boyfriend?"
The Bro: "Come on baby, you know I can't do that. It's Beast Night with the guys."
Verb:
Your friends: "Are we Beasting tonight?"
You: "OFYB!"