To exit a party, bar or other social gathering in a stealthy manner without saying goodbye to ones friends. Often done as a way of avoiding friends trying to prevent you from driving drunk or to escape a bad hookup.
Person 1: Dude what the fuck happened to you last night, we were all partying and then I noticed you were gone. What the fuck, you didn't even say goodbye.
Person 2: I was so wasted I had to give you all a riverside-goodbye.