[abritinthebay]

True, "fiat money" would technically be "inconvertible paper money made legal tender by a government decree."

Bitcoin by contrast is "inconvertible digital money made legal tender by no-one because it's not legal tender".

So.. it's fiat in the sense that "by fiat" sense - which is where fiat money as a term comes from, but not in the strict "fiat money" sense of the phrase.