The after effect of smoking too much marijuana. It is what occurs the next morning or day after you smoke a lot the night before. Symptoms of being muffined include waking up late, feeling really full, waves of being high, lack of attentiveness, and still having odd food cravings. Similar to an alcohol hangover for marijuana only it doesn't suck.
Oh dude, I am so muffined right now. Last night was dope.