A bout of coughing caused by the accidental inhalation of food particles while eating. Although Muffin Lung does commonly occur when eating muffins, any food (especially those with a low moisture content) can potentially trigger it. Heavy mouth-breathers are especially prone to Muffin Lung.
Slow down there, champ, you don't want to get Muffin Lung!
Sorry I missed your wedding, I was stricken with Muffin Lung.