I posed this question to answer it myself. Although several such items already exist on Candid-forum, I wanted the question to be more precisely worded.
Money is such a crucial aspect of modern life that it is hard to imagine without it. I mention 'modern-day' existence because money has been a phenomenon of human commerce since ancient times.
Accordingly, it should come as no surprise that every language seems to have both 'official' (formal) terminology for money as current and ney in its various specific denominations within that society.
A list of terms—including vernacular and slang terms—follows in both US and UK English. Of course, numerous other nations use a form of English besides the US and the UK, but they will also have their own currencies. To keep this somewhat manageable, I will limit my notes here to the US and UK.
Food Metaphors
It's striking that so many terms for money are metaphors for food. I surmise that this is because one needs money to buy food — one of human survival's basic needs (along with clothing and shelter). Here are some of the principal food-metaphor terms for money (mainly US), including several that refer specifically to baked goods:
- bacon
- dough
- bread (including 'bread-and-honey,' Cockney rhyming slang for 'money')
- biscuits (sometimes 'Bisquick,' from the US brand name for a boxed quick-bread mix)
- cake
- broccoli
- cabbage
- cheddar (sometimes simply 'cheese')
- guac, referring to the green color of guacamole
Other Slang Terms (with some notes on origins)
- Clams: a slang term for 'dollars,' probably based on the use of clams as food, but on the clamshells that Native Americans once used in California.
- Dead presidents is a slang term for banknotes generally, derived from the images of Presidents and other politicians on US banknotes.
- dosh: (attested in the UK since 1953, but also now sometimes heard in the USA) slang for 'money' generally, sometimes with the sense of 'ready money' or 'cash.' (Thought by some to come from the Russian Дош doš, in a slang sense of 'nose,' but this is not certain; Дош itself means 'word, matter, deed.')
- fetta: (apparently not from the Italian 'confetti,' but from the Spanish [mostly Mexican] feria meaning 'change' or a small amount of money)
- frog skins (presumably from the color of US paper money)
- greenbacks (again, a reference to the color of US paper money)
- Mazuma (attested from 1875–80; purportedly from the Hebrew *זמן z-m-n (a root used for words relating to time, including fixed measurements of time), via Yiddish מזמן mezumen' cash' (perhaps meaning 'fixed' or 'set' denominations of currency).
- Semolina or simoleon (attested in USA from ca 1896, as slang for a dollar bill; of uncertain origin, but perhaps from 'Simon,' which is said to be a 17th-century British slang term for the sixpence coin, and possibly also formed on analogy with the name 'Napoleon')
- Scroll, scrilla, skrill (perhaps from 'scroll,' referring to a stack of banknotes rolled up)
- wonga (said to be the Romani term used in the UK for money)
Money Terms Based on the Currencies of Other Cultures of Nations
- dinero (the generic Spanish word for 'money,' but originally an actual currency in Spain — the word based on the Latin denarius, like the Arabic and Central-European 'dinar')
- Ducats (from Ducato, the gold-coin currency of medieval Venice that became widely used internationally)
- pesos (Mexico)
- shekels (sometimes used with anti-semitic insinuations)
Names for Various Denominations of US Currency (some now archaic)
- 5-cent piece: a 'picayune' (from French picaillon). The word was initially used in Florida and Louisiana to refer to the Spanish half-real, i.e., ½ of a Real de an ocho (the original' piece of eight' beloved of pirates). In modern US English, 'picayune' is principally used (if at all) as an adjective that means 'trivial' or 'petty.'
- 25-cent piece: 'two bits' (now archaic), the 'bit' formerly referring to 1/8 of the US dollar; until 1794, there was a US 'bit' coin worth 12.5¢.
- $5: known as a 'fiver' (for obvious reasons, but I surmise borrowed from UK usage — the £5 note). Also known as a 'fin' or 'Finn' (from Fünf, the German word for 'five'), or as a 'five-spot' (perhaps on analogy with the playing cards that have five pips on them)
- $10: known as a 'sawbuck' (a 'sawbuck' is a type of wooden sawhorse made to hold wood conveniently for sawing; the vertical portions are X-shaped, i.e., in a shape that looks like the Roman numeral for 10, i.e., 'X'). Also known as a 'ten-spot' or simply a 'tenner' — probably also borrowed from UK usage — or, rarely, a 'Hamilton,' from the image of that US President.
- $20: known as a 'Jackson,' from the image of that US President.
- $50: known as a 'frog' (in the context of betting on horse racing); see above on 'frog skins' and 'greenbacks.'
- $100: known as 'Benjamins' or 'Franklins,' from the image of that 18th-century US statesman. Also known as a 'C-note,' from the Latin centum (hundred), abbreviated in Roman numerals as 'C.'
Obsolete UK Terms (from the older pounds/shillings/pence system, based on 12s and 20s instead of the current decimal system, which is modeled on the US dollar and has been in use since 1971), with some slang informal or slang terms that referred to them
- penny (plural' pence,' but from the period before there, were 'new pence' now abbreviated as 'p'😞 1/240 of a pound or 'quid.' Also, thus, 1/20 of a shilling or 'bob.' For hundreds of years, the abbreviation for old pence was 'd,' an abbreviation of the Roman coin term denarius. She was also known as a 'copper,' from the metal used to mint pennies.
- thruppence: the 'three-penny bit' (or 'tuppeny bit' as informally pronounced) was, naturally, worth three pennies. But at the period when this was in use, the coin was made of silver. Also known as a 'joey.'
- Farthing: ¼ of a penny. Also known as a 'mag.'
- Half-penny: ½ of a penny, worth two farthings. (Informally pronounced as ‘hay-any’; a ‘ha’porth’ = ‘worth a halfpenny,’ i.e. a tiny value or trivial amount)
- Sixpence: a coin worth six pennies, i.e., half of a shilling. Also known as a 'tanner.'
- Shilling: a coin worth 12 pennies, known as a 'bob.' There were 12 (not 10) pence in a shilling and 20 shillings to the pound. The abbreviation for 'shilling' was 's.' (The word is derived from Anglo-Saxon skilling, which may be from the Proto-Germanic skiljaną 'cut, split, divide' — derived in turn from Proto-Indo-European *(s)kelH- (itself meaning 'cut, separate')
- florin: two shillings; ⅒ of a sovereign. Also known as a 'two-bob bit.' (The original 'florin' was a gold coin minted by the medieval Republic of Florence and became a predominant trade coin throughout Western Europe.)
- half-crown: worth two shillings plus sixpence, and written '2s 6d.'
- crown: five shillings; ¼ of a sovereign.
- Half-sovereign: worth 10 shillings or two crowns; ½ of a sovereign.
- guinea: a gold coin worth £1/1s, i.e. 21 shillings. (Minted from 1663 to 1813.) The term may still be heard in auction or horse-racing contexts.
Some Even Older UK Terms
- Groat: a four-penny coin. There was also a half-groat.
- Ninepence: not an English coin, but the 16th-century Irish silver shilling was worth nine pennies in England. Similarly, in early New England, a Spanish silver coin was worth nine pennies and thus called 'ninepence.'
- Tuppence: a two-penny coin. A short-lived denomination, minted mostly just between 1797 and 1848, but the term 'tuppence' became proverbial for a tiny amount of money, or — by extension — a negligible value.
Other Words and Phrases Referring to UK Currency
- The sign for pounds sterling (£) is an abbreviation of the Latin libra, a 'pound' by weight (pond). The word also came to be used for a set of scales for weighing.
- Penny-wise and pound-foolish: i.e., distracted (by more minor, unimportant details) from larger, more critical ramifications.
- penny-dreadful: (attested from the 19th century) popular novels, often lurid in plot or style
- Ten-a-penny: cheap, plentiful.
- in for a penny, in for a pound: fully committed to a goal
- tuppenny-ha'penny: a disparaging term meaning 'cheap' or 'worthless'; said of people as well as of things
- three-and-fourpence: a rhyming-slang term (not necessarily Cockney) for '[military] reinforcements.'
This is undoubtedly only a partial list, but it may serve as a springboard for further discussion on Quora or elsewhere.
For more on UK money terms, both official and slang,