This term was coined by Daniel Krawisz, Director of Research at Satoshi Nakamoto Institute, in an article in 2014. It means the process of replacing fiat currency with Bitcoin.
Krawisz describes Hyperbitcoinization as a “voluntary transition from an inferior currency to a superior one, and its adoption is a series of individual acts of entrepreneurship rather than a single monopolist that games the system.”
He argues that, similarly to hyperinflation, once this process starts it will be impossible to stop it and there will be no going back to the previous monetary system.