Marty McFlying 

Riding a skateboard while under the influence of marijuana where the experience can be compared to riding a hoverboard from Back to the Future 2.

"Man, I blazed before taking the board out. I was Marty McFlying all afternoon!"

Marty McFlying by D2U3R4 May 8, 2009

Marty McFlying 

To walk backwards haphazardly, usually resulting in an unwanted encounter or physical altercation. Derives from Marty McFly from "Back to the future", as this action usually precedes a very bad event.

That kid over there was Marty McFlying all over the store and knocked down the tower of sodas.

Marty McFlying by F. Millmore April 23, 2010

Marty McFlyin 

Alternative word for “Blacking out” Minimum of 4 hours or more. Going back to the future due to incoherence. Time traveling is what your really doing.

I got so fucked up last night. I was Marty McFlyin the entire night.

Marty McFlyin by Son of Robert February 17, 2019