Yemeni fils are the currency used in Yemen, but there are several synonyms that can refer to it. The most common is simply the "Yemeni rial", which is the official name for the currency. Other synonyms include the "Yemeni yen", "Yemeni dollar" or just "Yemeni money". These can often be heard in informal settings, especially by expats or those who deal in foreign currencies. It's important to note, however, that the official name for the currency is the Yemeni rial and this is what you'll find on bank notes and official documents.