Since we're still making our way through the alphabet, this vacation will fall in with my crimes, criminal law & courtroom procedure for crime fiction writers.
Vacation: The annulment of a previous judgment or decision, the act of setting aside or canceling.
This motion is usually filed by a party to a lawsuit who lost the suit by default because they failed to appear in court. The mover must show the court that the judgment was issues in error, usually because the moving party was not properly served and was not aware he was expected to appear in court.
You're basically saying, " judge, this is unfair. I wasn't even aware of the suit so I did not have an opportunity to defend against the allegations of wrongdoing ."
You are asking the judge to vacate the judgment against you and order a new trial .