Noun: An extra piece of food that you cook with no intention of consumption for the current meal, but with knowledge of the fact that you will be hungry again shortly after. (Also applicable to intentionally ordering extra food at a restaurant in order to fulfill the same purpose)
Jack: Why are you cooking four hamburgers for dinner John? I told you that Kim couldn't come and it would just be the three of us for dinner!
John: Dude relax, I'm just making some auxiliary food! You know I'm gonna be hungry again later.