1. An annual celebration once held in Beaver Dam, WI, over Memorial Day weekend where softball teams drank heavily and bands played songs like "Radar Love" and "Keep Your Hands to Yourself." The event's name was changed subsequent to a story in Hustler Magazine where pictures of the Beaver Motel and a sign outside of Beaver Dam which read "Home of 15,000 Busy Beavers."
2. Colloquial euphemism used by heterosexual males and homosexual females to describe a party worth staying at all night long.
2. Dude, this party is a total beaverfest, don't invite any of your guy friends.