McMunchie
Replacing the top bun of a McDouble with a whole McChicken sandwich from McDonalds. The $2 price tag makes it a favorite among broke pot-heads.
Dude, after I smoked a bowl, I bought a McMunchie with some change I found in my car.
McMunchies
The act of being extremely hungry while in a state of intoxication, where getting to McDonalds seems like a "do or die" situation. No other food will suffice unless it is from McDonalds. The agent may do questionable things to get to a McDonalds, or perform extreme actions in order to acquire a meal from McDonalds.
Man I was so bombed last night and I had the worst McMunchies, I took a $55 cab just to get there. Haven't had McMunchies that bad in a while.