So, are you disregarding the definition altogether?
No, I am saying there is a problem with the definition. [...]
Yes, but you can't arbitrarily redefine words. People need to understand each other, and that's why there are words with agreed meaning.
And the agreed meaning of fiat currency is a currency which value is regulated by a government.
That's not the definition of fiat. [...]
Let's see what the Internet says about it:
Fiat money is currency which derives its value from government regulation or law.
Currency that a government has declared to be legal tender, but is not backed by a physical commodity.
money (as paper currency) not convertible into coin or specie of equivalent value
Paper money or coins of little or no intrinsic value in themselves and not convertible into gold or silver, but made legal tender by fiat (order) of the government.
To be fair, from my quick search, there's one site (Merriam Webster) that mentions nothing about the government; but others do. So, you can't just say That's not the definition of fiat when most people disagree with you.