A fine-ass chick with perfect buttox and breasts. She can lead a guy on with just her ass and is usually stubborn and hard to handle. Sexually she is omg....the best. But watch out they are known to knee you in the balls at times.
1) Mom, I need you to call me off of school. I seem to have a severe case of muffitis...it's spreading like rapid fire and I don't want anyone else to catch it!!!
2) Me and Dooch wanted to go to Walmart to ride the bikes, but our pussy of a friend Michael was opposed to the idea. He must have had a hint of muffitis.
Unlike what the name suggest, this is not an inflammatory condition. The term is used to refer to people who always complain and have a general negative attitude toward self and others. Verb: muffing.