An indeterminately great amount or number
There are a zillion fast food restaurants around here.
You've told me a zillion times.
I'd sue your ass and the county and everyone else in sight for a zillion bucks.
He'd been fevered for a zillion years, trapped in the tiny cell in ever-changing forms, always in darkness.
After a zillion years sleeping on the floor, I won't waste another night outside a real bed.