What is Prep-rally?
1.
pre-sporting event school assembly given to support the sports team that only the preps want o go to
That prep-rally this afternoon went on forever.
2.
A rally of like minded morons. Usually reserved for a group of people who gather together to psyche themselves up before a pointless/meaningless/worthless event.
The (insert any group) convention really turned into a prep-rally.
See
