When too many items on a sandwich such as tomatoes, lettuce and mayo cause the meat to slide off the sandwich resulting in total sandwich destruction.
Todd bites into his sandwich, the meat falls out the back and the remainder of the sandwich crumbles in his hands.

Frank-"Woah! tectonic meat slippage. Better get a fork, Todd"
by killersbytrade January 31, 2010
Get the Tectonic Meat Slippage mug.