Gold franc is a term used to describe a currency unit that is primarily composed of gold. However, there are several other synonyms that can be used in place of this term. For example, it can be called a gold coin or a gold currency, as these alternatives accurately reflect the underlying value and composition of the monetary system. Another similar phrase is a gold standard unit, which refers to a currency that is backed by gold reserves. These synonyms can be helpful when discussing the history or economics of currency systems, or when exploring the role of gold in the global economy.