After a good doggie style romp, the jizz left on the tip of your cock gets rubbed into the chicks bunghole. A little poop gets mixed in during the rubbing and you muck it up.
After banging the bitch doggie style, I blew on her back. Then I mucked it up for a bit, before banging her sister.
by Dr. Davidoff Vilson March 28, 2005
Muckit is when you take your cock and push it around in your bitches asshole...you smoosh around her shit and your gizz.
by Dr. Davidoff Vilson March 22, 2005
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