Fiat monies refer to currency that derives its value from government regulation rather than being backed by a commodity such as gold. There are several synonyms for the term, including paper money, legal tender, and currency. Another synonym is flat money. This type of currency is often criticized for its vulnerability to inflation and devaluation, especially when the government issues too much of it without sufficient economic growth. Despite these criticisms, fiat money is the most widely used form of currency in the world and is essential to the functioning of modern economies. Other synonyms for fiat money include banknotes, cash, and notes.