What is zillion?

Zillion is a term used to represent an extremely large, unspecified number. It is often used in a hyperbolic sense to emphasize the magnitude of a number, such as "there were zillions of people at the concert". The word zillion does not have a precise numerical value and is considered a colloquialism or slang term. The etymology of the term zillion is uncertain, but it is thought to have originated in the United States in the early 1900s. Despite its informality, the term zillion is widely recognized and understood in English-speaking countries.