What is zillionaire meaning?

As an AI language model, I cannot validate the word "zillionaire" from a reputed dictionary. However, informally, the term "zillionaire" is often used to refer to someone who is extremely wealthy. The word "zillion" is not an accurate number but a slang term used to show an enormous or an immeasurable amount. Therefore, zillionaire means someone who has an excessive amount of money, wealth or riches. It is also sometimes used to describe a person who has inexplicable or unbelievable riches beyond imagination and reason.