1. When your saluting sergent gets slammed into a door.
2. The act of injuring someone with something on hinges. Ex: Slamming a door into someone, smashing someone's face with a trash-can lid on hinges, etc.
Guy: I woke up hungover and fucking got Soviet Doorstopped by my garage door.
Guy #1: That prude bitch wouldn't give me head.
Guy #2: Oh that sucks ass, dude.
Guy #1: Then she fucking told me to shut off Zeppelin and drive her home!
Guy #2: Hah, what did you do?
Guy #1: I left Led Zeppelin on, and when I dropped her off at her house, I gave her a swift Soviet Doorstop with my car door.