muck up day is usually when year 12s do a prank similar to senior pranks. mostly used and done in australian public schools
by eedeen November 06, 2021
by ol upchuck November 30, 2020
The time period when Valve released a TF2 update with spaghetti code that forced the crate series to always drop unusuals. This resulted in the unusual market crashing with absolutely no survivors left.
by FL4ym3Burn July 26, 2019
A day where usually year 12s do things that are not allowed e.g tying a year 7 to a pole ect. mostly done in Australia.
Year 12 N1 : What are you doin for Muck Up day?
Year 12 N2 : I’m starting a water balloon fight on the oval
Year 12 N2 : I’m starting a water balloon fight on the oval
by eedeen November 11, 2021