About a week ago, I used the word 'argot' when I became aware that I didn't know what I was talking about. I immediately thought, 'Confessions of Ignorance, here I come!' However, I was away and time passed. Then tonight, I was at a discussion group I go to, and a man whose great strength and sometimes great failing is his linguistic obsession brought up the very word and was able to define it for us.
So let's start from what I would have guessed. I would have said that 'argot' was a sort of slang or dialect.
What he said was that 'argot' is a specialized language used in a social setting. 'Jargon' is a specialized language in a professional setting. And slang is actually something that has already passed from the language. We recognize something as slang when we no longer use it. In common use, of course, we think of slang as being something different. We use it to mean a kind of relaxation or alternative to 'proper English'. Likewise, what might seem an 'argot' to one person might be 'jargon' to another. Someone raised the point that a thief's language might be argot to someone who is not a thief, but jargon, i.e., a professional, specialized language, to a thief.
Okay,(But 'okay' is also slang that doesn't recognize itself as such yet, according to our expert.) let's see what the dictionary has to say on this matter.
Argot: a specialized language or set of idioms used by a particular group. And they use the very example we mentioned--thieves' argot. But in the next definition we have 'slang or jargon used by a particular group.'
So we differentiate, only to have it all jumbled together again.
Jargon: Whoa! Yes, it is a specialized or technical language of a trade, profession or similar group. But it can also mean nonsensical, meaningless, incoherent talk. Or a hybrid language, like pidgen. Or having a pretentious vocabulary, convoluted phrasing, and vague meaning.
Interesting how a a very precise language may come to sound vague or meaningless to those who are not within the circle.
Slang: Well, again it is used interchangeably with both argot and jargon. But as my friend said, the salient characteristic is that it is short-lived coinage. In fact, I think he was saying that the 'sl' in slang stands for that. The idea of slang is to replace the standard term in favor of raciness, irreverence or humor. You can see how it might generally be short-lived, but how certain terms that really hit the mark might be around for awhile.