an informal social gathering consisting exclusively of heterosexual males. Usually the attendees of a sausage party would be delighted if only some girls would show up. Charlottesville's Horrid Crash Pad and Oberlin's Frank's Afterhours were two places that were famous for their sausage parties.
Read about the first time I heard the term "sausage party."
Read about a pre-planned sausage party. Believe it or not, sometimes the chicks aren't even invited!