N. the disgusting, bottom part of the muffin that, it would seem, was ignored in the delegation of yummy muffin ingredients like chocolate chips, blueberries, and nuts. They are most commonly discarded or left to rot on a lunch tray.
Stina Shall: Namie, why haven't you finished your muffin?
Lyme Ninja: Pft. I never eat the Muffinbutts.