pronounced (ba-jill-ion). It’s an overexaggeration of a number of things. It’s a combination of million and billion. it is commonly used in a sarcastic way, but can be said in a serious disagreement or conversation without seeming unintelligent.
two girls walked into a very expensive clothes store.
girl 1: "wow, these clothes must all cost a bigillion dollars!"
girl 2: "i know right!"