Drinking a glass of wine from Taman—the peninsula that pokes out of the Russian coast towards Crimea, across the strait from Kerch—I fell to wondering where the name came from. The answer turns out to be that nobody is sure: there is no settled etymology and no unarguable evidence for any of the candidates. But, as usually happens, a chasm opened along the way, and it was full of stars.
The largest number in the world
On one theory, Taman—and with it Tmutarakan, the mediaeval principality that stood there, whose name has since become Russian shorthand for the back of beyond—goes back to the Turkic *tümen.
That word meant ten thousand: the largest number the ancient world had a name for. And because ten thousand of anything is more than a person can actually picture, it also meant, simply, uncountable.
English has been through exactly the same door. Our myriad is the Greek myrias, ten thousand—a precise figure, used for counting soldiers and drachmas—which drifted, over centuries, into meaning “a great many, beyond counting.” When you say a myriad of reasons, you are using a number as a shrug. Russian did the identical thing with its own borrowing of tümen, which fell together with the native word for darkness, so that the Russian for “an enormous number” is, etymologically, “a darkness of darknesses.”
Among Turks and Mongols the word went the military route: a tumen was the largest formation in the army, ten thousand horsemen. Anyone who has read about Genghis Khan has met it.
And it is still in your newspaper. The Iranians reckon money in tomans—the unit was originally ten thousand dinars, and although the official currency is the rial, everybody in Iran quotes prices in tomans to this day. A Mongol cavalry division, sitting quietly in a Tehran price tag.
Further east, and further back
The Turkic *tümen was itself borrowed—from one of the Tocharian languages, the Indo-European speech of the Buddhist population of the Tarim Basin, in what is now Xinjiang, between the first millennium BC and the first millennium AD. And Tocharian had taken it, with the same meaning, from Middle Chinese.

In Chinese the meaning was carried by the character 萬 (simplified 万), which the various Chinese languages pronounce with strikingly different initials: /wàn/ in Mandarin, /maan/ in Cantonese, /bān/ in Southern Min. The Old Chinese pronunciation is reconstructed as something like /*m̥ʰraːds/—which bears an unnerving resemblance to the Greek myrias.
Is there a connection? Almost certainly not. Two unrelated language families arriving at ten thousand by way of similar noises is the kind of coincidence that has wrecked a great many amateur etymologies. But it is a good one.
And now look at the character

Look at the traditional form. What does it remind you of?
Quite so: a scorpion. The original sense of the pictogram is lost beyond recovery, but one may suppose that the idea of uncountability—which later attached itself to the largest number the ancient world possessed—had something to do with scorpions arriving in quantity. One thinks of a scene from Indiana Jones.
So a glass of wine from the Kuban has taken us across Western Siberia to the Tarim Basin, by way of a Tehran price list and a Mongol cavalry division. Travel with us—and pay no attention to the scorpion’s curse.