It's probably older than you think.
This little self-cautionary maxim comes in handy in many parts of life, I find. It's certainly useful in understanding language.
Who knew, for instance, that smooch, a popular 20th-century colloquialism, went back to 1578? I didn't, until I ran across it in Fowler's while looking up something else. (The path to knowledge is often a detour.)
And dollar turns out to be even older – it goes back to the 1550s. Why does a relatively young nation have such a relatively old name for its money? I started onto this detour while trying to sort out what to call the Chinese currency.
It goes by two different names, and I'm sure I've not been alone in my bafflement. Sometimes it's called the renminbi and at other times it's the yuan. And it doesn't help that "renminbi" doesn't sound particularly Chinese.
But then I ran across this from economist Paul Krugman, writing last year when exchange rates were once again in the news:
"[R]enminbi is the name of China's currency; but yuan is the denomination of bills, the unit in which prices are measured, etc. The closest parallel I can think of is Britain's currency, which is sterling, but whose unit is the pound."
He explained further, "[T]alking about the number of renminbi per dollar is,… as I understand it, wrong – as wrong as talking about the number of sterling per dollar. Renminbi is the currency, but not a unit of the currency."
There you are – clear as mud? No wonder Krugman joked that the whole thing is "a sinister plot by the Chinese designed specifically to deter people from discussing Chinese currency policy." Note that even a Nobel laureate chose to fudge a bit with "as I understand it."
This leads to another question: How did the British end up with their double terminology? Sterling was originally a silver penny. A pound of such pennies, about 240 of them, was the original "pound sterling."
As I write, however, silver is trading above $23 an ounce, and the British pound is at $1.57. Inflation has gotten its licks in over time. But at least we know the back story.
What about the dollar? This nursery rhyme got my wheels turning:
"A diller, a dollar, a ten o'clock scholar,
What makes you come so soon?
You used to come at ten o'clock,
And now you come at noon."
I don't have a date for this, but nursery rhymes tend to be old. A "dollar" in a nursery rhyme, even as a bit of nonsense filler, suggests there were dollars before our greenback.
The Online Etymology Dictionary traces dollar to the Low German word daler. This came from the Joachimstaler guilder, a coin minted from the silver from a famous mine near Joachimstal. "Joachimstaler guilder" was shortened, first to "Joachimstaler" and then simply "taler."
These early silver "talers" circulated among the German states from 1519 on. Denmark and Sweden had "talers" of their own, and the English colonists in America used a similar term for Spanish pieces of eight. When the Continental Congress needed to establish the new republic's new currency in 1785, Gouverneur Morris and Thomas Jefferson suggested it be called the dollar. As the Online Etymology Dictionary puts it, "[T]he term was widely known, but not British."