And yet, while he behaved thus toward his friends and acquaintances, he did not show himself cruel or inexorable even to his enemies, but let off scot-free many of those who had come into collision with him personally and released many who had actually made war against him, even giving some of them honors and offices (Dio Cassius. Dio's Roman History: with an English Translation. Volume 32 of Loeb classical library. Edited and translated by Earnest Cary, and Herbert Baldwin Foster. Book XLIV. 377, 379).

There's an interesting phenomena known as folk etymology. That's when we have what seem like perfectly reasonable, even common sense, assumptions about the ancestry of words that, however reasonable on the surface, are in fact wrong.

Not too long ago, I had some one tell me that the phrase "scot free" referred to the fact that the Scots, that is Scottish people, never pay for anything, and are known to go to great lengths to avoid paying, including abandoning a dinner party at a restaurant.

This is of course, scurrilous, bigoted, and linguistically wrong.

"Scot" in scot-free is a word borrowed from Old Norse into Old English, in the form scotfreo It meant that something was free (freo) of the excise tax or punitive fine known as a scot. In modern English, the scot is "Money assessed or paid" (AHD s.v. scot). Modern English borrowed scot from Old Norse skot. The skot is a "contribution, reckoning," via Old English sceotan, "to pay, contribute" and cognate with Dutch schot, and German Schoß. Scot, then, is actually related to modern English (or rather Modern U.K. English" shot, as in as in "I'll pay the shot at the bar, and be on my way" where we would use "tab" in American English, to refer to paying a bar bill. Shot and scot both go back to the proto Indo-European root * skeud-.

The actual definition of modern scot-free is:

1. Without having to pay: got away from the restaurant scot-free.
2. Without incurring any penalty or punishment: came away from the incident scot-free.

This is exactly what the quotation from Dio Cassius is about; avoiding a fine or punishment. It has nothing to do with being Scottish. Scot as in "he's a Scot, from Scotland" is actually not at all related to scot-free. The scot of Scotland is a word that is first used by Latin writers to refer to a group of Celts in Ireland (the same tribes later migrated to Scotland), but we really don't know where the word originated. the sc- suggests that it is either Celtic or Germanic in origin, but we don't know. It is, however, very unlikely that the two words scot/Scot are not related, in part because of the ages of the two (Scot is older) and the nature of linguistic change in Indo-European languages.

The next time someone tells you that scot-free means "cheap as a Scot," or whatever, please do let them know that they are indulging in two inaccurate statements at once, as well as publicly engaging in folk etymology.