For shits and giggles, here's a potted history of the coinage and currency words we use:

The Romans were keen on "denari" where 12 denari was worth 1 gold "solidus" and cut from a silver "libra" or pound of silver, 240 denari per pound. This coinage lasted over a thousand years. There were also "sisteri" though the denari morphed into "dinar" of modern Arab usage.

Most coins from Middle Ages on were based on names like "ducat" or "real" which come from Duke and Royal, Venice and Spanish/Portuguese Empires. The latter also had "escudos" which means shield and the gold escudo was worth 16 silver reals and then the "doubloon" was a double escudo (same as louis d'or). The "dollar" came from Spain and was worth 8 reals - hence pieces of eight - minted in silver and the basis of the US dollar. It morphed into the "peso" or piece in modern coinage. The Spanish silver dollar was based on the German "thaler" which was also used throughout eastern Europe and lives on as the dollar today.

The "groat" was an English silver coin, worth four "pennies" derived from the Dutch and Italian 'great' coins. Groats were replaced by pennies and shillings, sixty six "shilling" being a pound of silver. Five "shilling" made a "crown" and two shillings equaled a "florin". Shillings were eventually replaced by pence and pounds and five "pence" was one shilling; a pound became 20 shillings. Pennies were divided into four "farthings" and a "guinea" was 21 shillings!