Again. You have an impressive ability to not state a single accurate argument.

Using the names of mental disorders as playground insults is disrespectful and irresponsible.

Invalid basis. That a negative character trait can in severe cases be a disability, does not mean that the negative character trait is. Nor is it a correct assumption that all uses of said character trait (adjective or noun form), implies the severity to be diagnosed as a disability. Even otherwise positive traits can be disabilities if they are in excess as to be disability. It really is as simple as that.

And if you say that narcissism as an insult is an established term

First, I have not said that. So again, invalid premise. Secondly, no one so far used narcissism "as an insult", but as a descriptive word. Which is more or less the function of language and words. The assumption that people meant to insult, and not be accurate, is on you.

I'll remind you that it got that way because people used the name of a disorder as an insult. As a slur.

Remind me of what now? Words for character traits exist. If a person has trouble remembering stuff, you might be "forgetful". If it is so severe that it impacts their quality of life, then it might be diagnosed as a disorder. Saying a person is forgetful doesn't mean it is used as an insult.

And no, the insult isn't drawn directly from greek mythology, because Greek mythology has the name Narcissus, not the noun narcissist. The noun narcissist was coined by psychologists talking about pathology.

Thanks for the etymology lesson. I think your argument is that if you use words that stem from psychology, coined to describe a type of character/personality, and that if the trait, if sufficiently severe is considered a disorder, that one cannot (should not?) be used it the same way as defined by psychologists? That's... Why wouldn't one be allowed to use words for the generally understood meaning of the words?

When a psychologist gives a person the diagnosis for having a disability as a result of "narcissism". They don't give the diagnosis as "narcissist". The diagnosis is called "narcissistic personality disorder".

You know why they add the last word of "disorder"? Because narcissist/ic is already described, and when it is diagnosed as a disorder, they call it a disorder.

A psychologist might not be comfortable with, or even use the somewhat reductive "a narcissist". But it's fine to use colloquially.

I've met plenty of people with varying degrees of narcissistic traits. When people sometimes refer to them as "a narcissist", they are being somewhat reductive. But seldom, if ever, has it been used as an insult for the sake of insult. And generally describe... Well, you can lookup the behavioural commonalities. I wouldn't say any one of them had it as a personal disability. And they all ranged somewhere from "you like to share the view from your perspective a bit much" to "self centered asshole".

Anyways. You caught me in a moment of being stuck, with nothing to do. I generally don't think this is worth while. Mostly good intentions tho, if you can believe it. Also in part enjoying to point out when people are being shit at forming an argument.