A zillion is a very, very large number. How large is it? When you want to exaggerate a number, use a zillion. It’s not a real number, but it’s used to express things that are nearly impossible to count.
It’ll cost zillions of dollars to send human beings to Mars.
Shopping the day after Thanksgiving is not fun because there are zillions of shoppers in the stores.
There are zillons of stars and planets in the universe.
I can give you a zillion reasons for not doing that.
Zillions of ants came out from under that old log when Jeff pushed it over with his foot.